Browsing by Author "Hartigan, Patrick"
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Item A JWST Preview: Adaptive-optics Images of H2, Br-γ, and K-continuum in Carina's Western Wall(IOP, 2020) Hartigan, Patrick; Downes, Turlough; Isella, AndreaWe present the first wide-field near-infrared adaptive-optics images of Carina's Western Wall (G287.38-0.62), one of the brightest and most well-defined irradiated interfaces known in a region of massive star formation. The new narrowband H2 2.12 μm, Br-γ and K-continuum images from Gemini South trace the photoevaporative flow from the cloud and identify locations where UV radiation from the surrounding massive stars excites molecular hydrogen to fluoresce. With a field of view of ~1farcm5 × 2farcm9 and spatial resolution between 60 and 110 mas, the new images show a spectacular level of detail over a large area, and presage what the James Webb Space Telescope (JWST) should achieve. The Wall is convex in shape, with a large triangular-shaped extension near its apex. The interface near the apex consists of 3–4 regularly spaced ridges with projected spacings of ~2000 au, suggestive of a large-scale dynamically important magnetic field. The northern edge of the Wall breaks into several swept-back fragments of width ~1800 au that resemble Kelvin–Helmholtz instabilities, and the southern part of the Wall also shows complex morphologies including a sinusoidal-like variation with a half-wavelength of 2500 au. Though the dissociation front must increase the density along the surface of the Wall, it does not resolve into pillars that point back to the ionization sources, as could occur if the front triggered new stars to form. We discovered that MHO 1630, an H2 outflow with no clear driving source in the northern portion of the Wall, consists of a series of bow shocks arrayed in a line.Item A New Look at T Tauri Star Forbidden Lines: MHD-driven Winds from the Inner Disk(IOP Publishing, 2018) Fang, Min; Pascucci, Ilaria; Edwards, Suzan; Gorti, Uma; Banzatti, Andrea; Flock, Mario; Hartigan, Patrick; Herczeg, Gregory J.; Dupree, Andrea K.Magnetohydrodynamic (MHD) and photoevaporative winds are thought to play an important role in the evolution and dispersal of planet-forming disks. We report the first high-resolution (Δ v ∼ 6 km s −1 ) analysis of [S ii ] λ 4068, [O i ] λ 5577, and [O i ] λ 6300 lines from a sample of 48 T Tauri stars. Following Simon et al. we decompose them into three kinematic components: a high-velocity component (HVC) associated with jets, and low-velocity narrow (LVC-NC) and broad (LVC-BC) components. We confirm previous findings that many LVCs are blueshifted by more than 1.5 km s −1 and thus most likely trace a slow disk wind. We further show that the profiles of individual components are similar in the three lines. We find that most LVC-NC and LVC-BC line ratios are explained by thermally excited gas with temperatures between 5000 and 10,000 K and electron densities of ∼10 7 –10 8 cm −3 . The HVC ratios are better reproduced by shock models with a pre-shock H number density of ∼10 6 –10 7 cm −3 . Using these physical properties, we estimate ##IMG## [http://ej.iop.org/images/0004-637X/868/1/28/apjaae780ieqn1.gif] $\dotM_\mathrmwind/\dotM_\mathrmacc$ for the LVC and ##IMG## [http://ej.iop.org/images/0004-637X/868/1/28/apjaae780ieqn2.gif] $\dotM_\mathrmjet/\dotM_\mathrmacc$ for the HVC. In agreement with previous work, the mass carried out in jets is modest compared to the accretion rate. With the likely assumption that the LVC-NC wind height is larger than the LVC-BC, the LVC-BC ##IMG## [http://ej.iop.org/images/0004-637X/868/1/28/apjaae780ieqn3.gif] $\dotM_\mathrmwind/\dotM_\mathrmacc$ is found to be higher than the LVC-NC. These results suggest that most of the mass loss occurs close to the central star, within a few au, through an MHD-driven wind. Depending on the wind height, MHD winds might play a major role in the evolution of the disk mass.Item ALMA Data Cubes and Continuum Maps of the Irradiated Western Wall in Carina(IOP Publishing, 2022) Hartigan, Patrick; Hummel, Maxwell; Isella, Andrea; Downes, TurloughWe present Atacama Large Millimeter/submillimeter Array observations of the continuum and line emission of 12CO, 13CO, C18O, and [C i] for a portion of the G287.38-0.62 (Car 1-E) region in the Carina star-forming complex. The new data record how a molecular cloud responds on subarcsecond scales when subjected to a powerful radiation front, and provide insights into the overall process of star formation within regions that contain the most-massive young stars. The maps show several molecular clouds superpose upon the line of sight, including a portion of the Western Wall, a highly irradiated cloud situated near the young star cluster Trumpler 14. In agreement with theory, there is a clear progression from fluoresced H2, to [C i], to C18O with distance into the photodissociation region (PDR) front. Emission from optically thick 12CO extends across the region, while 13CO, [C i] and especially C18O are more optically thin, and concentrate into clumps and filaments closer to the PDR interface. Within the Western Wall cloud itself we identify 254 distinct core-sized clumps in our data cube of C18O. The mass distribution of these objects is similar to that of the stellar initial mass function. Aside from a large-scale velocity gradient, the clump radial velocities lack any spatial coherence size. There is no direct evidence for triggering of star formation in the Western Wall in that its C18O clumps and continuum cores appear starless, with no pillars present. However, the densest portion of the cloud lies closest to the PDR, and the C18O emission is flattened along the radiation front.Item Emission-line Data Cubes of the HH 32 Stellar Jet(IOP, 2020) Hartigan, Patrick; Hillenbrand, Lynne A.; Matuszewski, Matuesz; Borges, Arlindo Chan; Neill, James D.; Martin, D. Christopher; Morrissey, Patrick; Moore, Anna M.We analyze data cubes of over 60 emission lines in the HH 32 stellar jet acquired with the Keck Cosmic Web Imager (KCWI). The data cover the less explored blue portion of the spectrum between 3586 and 6351 Å and have both high spectral (R ~ 10,000) and spatial (lesssim1'') resolution. The study includes all three major ionization states of oxygen, three Balmer lines, multiple lines of Fe ii and Fe iii, and the first data cubes ever acquired for important unblended diagnostic lines such as He ii λ4686, Ca i λ3933, and Mg i] λ4571. The data cubes generally sort according to excitation and have a relatively continuous progression from the highest-excitation ions (He ii, O iii) through the intermediate-excitation ions (O i and H i) to the lowest-excitation ions (Ca ii and Mg i). Merging the KCWI cubes with Hubble Space Telescope images leads to several new insights about the flow, including evidence for bow shocks, partial bow shocks, spur shocks, Mach disks, jet deflection shocks, a wiggling jet, and potential shock precursors. The most surprising result is that one of the velocity components of Fe ii in the Mach disk suddenly increases in flux relative to other lines by a factor of two, implying that the Mach disk vaporizes dust in the jet. Hence, jets must accelerate or entrain dust to speeds of over 300 km s−1 without destroying the grains.Item PDRs4All - II. JWST’s NIR and MIR imaging view of the Orion Nebula(EDP Sciences, 2024) Habart, Emilie; Peeters, Els; Berné, Olivier; Trahin, Boris; Canin, Amélie; Chown, Ryan; Sidhu, Ameek; Putte, Dries Van De; Alarcón, Felipe; Schroetter, Ilane; Dartois, Emmanuel; Vicente, Sílvia; Abergel, Alain; Bergin, Edwin A.; Bernard-Salas, Jeronimo; Boersma, Christiaan; Bron, Emeric; Cami, Jan; Cuadrado, Sara; Dicken, Daniel; Elyajouri, Meriem; Fuente, Asunción; Goicoechea, Javier R.; Gordon, Karl D.; Issa, Lina; Joblin, Christine; Kannavou, Olga; Khan, Baria; Lacinbala, Ozan; Languignon, David; Gal, Romane Le; Maragkoudakis, Alexandros; Meshaka, Raphael; Okada, Yoko; Onaka, Takashi; Pasquini, Sofia; Pound, Marc W.; Robberto, Massimo; Röllig, Markus; Schefter, Bethany; Schirmer, Thiébaut; Tabone, Benoit; Tielens, Alexander G. G. M.; Wolfire, Mark G.; Zannese, Marion; Ysard, Nathalie; Miville-Deschenes, Marc-Antoine; Aleman, Isabel; Allamandola, Louis; Auchettl, Rebecca; Baratta, Giuseppe Antonio; Bejaoui, Salma; Bera, Partha P.; Black, John H.; Boulanger, Francois; Bouwman, Jordy; Brandl, Bernhard; Brechignac, Philippe; Brünken, Sandra; Buragohain, Mridusmita; Burkhardt, Andrew; Candian, Alessandra; Cazaux, Stéphanie; Cernicharo, Jose; Chabot, Marin; Chakraborty, Shubhadip; Champion, Jason; Colgan, Sean W. J.; Cooke, Ilsa R.; Coutens, Audrey; Cox, Nick L. J.; Demyk, Karine; Meyer, Jennifer Donovan; Foschino, Sacha; García-Lario, Pedro; Gavilan, Lisseth; Gerin, Maryvonne; Gottlieb, Carl A.; Guillard, Pierre; Gusdorf, Antoine; Hartigan, Patrick; He, Jinhua; Herbst, Eric; Hornekaer, Liv; Jäger, Cornelia; Janot-Pacheco, Eduardo; Kaufman, Michael; Kemper, Francisca; Kendrew, Sarah; Kirsanova, Maria S.; Klaassen, Pamela; Kwok, Sun; Labiano, Álvaro; Lai, Thomas S.-Y.; Lee, Timothy J.; Lefloch, Bertrand; Petit, Franck Le; Li, Aigen; Linz, Hendrik; Mackie, Cameron J.; Madden, Suzanne C.; Mascetti, Joëlle; McGuire, Brett A.; Merino, Pablo; Micelotta, Elisabetta R.; Misselt, Karl; Morse, Jon A.; Mulas, Giacomo; Neelamkodan, Naslim; Ohsawa, Ryou; Omont, Alain; Paladini, Roberta; Palumbo, Maria Elisabetta; Pathak, Amit; Pendleton, Yvonne J.; Petrignani, Annemieke; Pino, Thomas; Puga, Elena; Rangwala, Naseem; Rapacioli, Mathias; Ricca, Alessandra; Roman-Duval, Julia; Roser, Joseph; Roueff, Evelyne; Rouillé, Gaël; Salama, Farid; Sales, Dinalva A.; Sandstrom, Karin; Sarre, Peter; Sciamma-O’Brien, Ella; Sellgren, Kris; Shenoy, Sachindev S.; Teyssier, David; Thomas, Richard D.; Togi, Aditya; Verstraete, Laurent; Witt, Adolf N.; Wootten, Alwyn; Zettergren, Henning; Zhang, Yong; Zhang, Ziwei E.; Zhen, JunfengContext. The James Webb Space Telescope (JWST) has captured the most detailed and sharpest infrared (IR) images ever taken of the inner region of the Orion Nebula, the nearest massive star formation region, and a prototypical highly irradiated dense photo-dissociation region (PDR). Aims. We investigate the fundamental interaction of far-ultraviolet (FUV) photons with molecular clouds. The transitions across the ionization front (IF), dissociation front (DF), and the molecular cloud are studied at high-angular resolution. These transitions are relevant to understanding the effects of radiative feedback from massive stars and the dominant physical and chemical processes that lead to the IR emission that JWST will detect in many Galactic and extragalactic environments. Methods. We utilized NIRCam and MIRI to obtain sub-arcsecond images over ~150″ and 42″ in key gas phase lines (e.g., Pa α, Br α, [FeII] 1.64 µm, H2 1−0 S(1) 2.12 µm, 0–0 S(9) 4.69 µm), aromatic and aliphatic infrared bands (aromatic infrared bands at 3.3–3.4 µm, 7.7, and 11.3 µm), dust emission, and scattered light. Their emission are powerful tracers of the IF and DF, FUV radiation field and density distribution. Using NIRSpec observations the fractional contributions of lines, AIBs, and continuum emission to our NIRCam images were estimated. A very good agreement is found for the distribution and intensity of lines and AIBs between the NIRCam and NIRSpec observations. Results. Due to the proximity of the Orion Nebula and the unprecedented angular resolution of JWST, these data reveal that the molecular cloud borders are hyper structured at small angular scales of ~0.1–1″ (~0.0002–0.002 pc or ~40–400 au at 414 pc). A diverse set of features are observed such as ridges, waves, globules and photoevaporated protoplanetary disks. At the PDR atomic to molecular transition, several bright features are detected that are associated with the highly irradiated surroundings of the dense molecular condensations and embedded young star. Toward the Orion Bar PDR, a highly sculpted interface is detected with sharp edges and density increases near the IF and DF. This was predicted by previous modeling studies, but the fronts were unresolved in most tracers. The spatial distribution of the AIBs reveals that the PDR edge is steep and is followed by an extensive warm atomic layer up to the DF with multiple ridges. A complex, structured, and folded H0/H2 DF surface was traced by the H2 lines. This dataset was used to revisit the commonly adopted 2D PDR structure of the Orion Bar as our observations show that a 3D “terraced” geometry is required to explain the JWST observations. JWST provides us with a complete view of the PDR, all the way from the PDR edge to the substructured dense region, and this allowed us to determine, in detail, where the emission of the atomic and molecular lines, aromatic bands, and dust originate. Conclusions. This study offers an unprecedented dataset to benchmark and transform PDR physico-chemical and dynamical models for the JWST era. A fundamental step forward in our understanding of the interaction of FUV photons with molecular clouds and the role of FUV irradiation along the star formation sequence is provided.Item PDRs4All - III. JWST’s NIR spectroscopic view of the Orion Bar(EDP Sciences, 2024) Peeters, Els; Habart, Emilie; Berné, Olivier; Sidhu, Ameek; Chown, Ryan; Putte, Dries Van De; Trahin, Boris; Schroetter, Ilane; Canin, Amélie; Alarcón, Felipe; Schefter, Bethany; Khan, Baria; Pasquini, Sofia; Tielens, Alexander G. G. M.; Wolfire, Mark G.; Dartois, Emmanuel; Goicoechea, Javier R.; Maragkoudakis, Alexandros; Onaka, Takashi; Pound, Marc W.; Vicente, Sílvia; Abergel, Alain; Bergin, Edwin A.; Bernard-Salas, Jeronimo; Boersma, Christiaan; Bron, Emeric; Cami, Jan; Cuadrado, Sara; Dicken, Daniel; Elyajouri, Meriem; Fuente, Asunción; Gordon, Karl D.; Issa, Lina; Joblin, Christine; Kannavou, Olga; Lacinbala, Ozan; Languignon, David; Gal, Romane Le; Meshaka, Raphael; Okada, Yoko; Robberto, Massimo; Röllig, Markus; Schirmer, Thiébaut; Tabone, Benoit; Zannese, Marion; Aleman, Isabel; Allamandola, Louis; Auchettl, Rebecca; Baratta, Giuseppe Antonio; Bejaoui, Salma; Bera, Partha P.; Black, John H.; Boulanger, Francois; Bouwman, Jordy; Brandl, Bernhard; Brechignac, Philippe; Brünken, Sandra; Buragohain, Mridusmita; Burkhardt, Andrew; Candian, Alessandra; Cazaux, Stéphanie; Cernicharo, Jose; Chabot, Marin; Chakraborty, Shubhadip; Champion, Jason; Colgan, Sean W. J.; Cooke, Ilsa R.; Coutens, Audrey; Cox, Nick L. J.; Demyk, Karine; Meyer, Jennifer Donovan; Foschino, Sacha; García-Lario, Pedro; Gerin, Maryvonne; Gottlieb, Carl A.; Guillard, Pierre; Gusdorf, Antoine; Hartigan, Patrick; He, Jinhua; Herbst, Eric; Hornekaer, Liv; Jäger, Cornelia; Janot-Pacheco, Eduardo; Kaufman, Michael; Kendrew, Sarah; Kirsanova, Maria S.; Klaassen, Pamela; Kwok, Sun; Labiano, Álvaro; Lai, Thomas S.-Y.; Lee, Timothy J.; Lefloch, Bertrand; Petit, Franck Le; Li, Aigen; Linz, Hendrik; Mackie, Cameron J.; Madden, Suzanne C.; Mascetti, Joëlle; McGuire, Brett A.; Merino, Pablo; Micelotta, Elisabetta R.; Misselt, Karl; Morse, Jon A.; Mulas, Giacomo; Neelamkodan, Naslim; Ohsawa, Ryou; Paladini, Roberta; Palumbo, Maria Elisabetta; Pathak, Amit; Pendleton, Yvonne J.; Petrignani, Annemieke; Pino, Thomas; Puga, Elena; Rangwala, Naseem; Rapacioli, Mathias; Ricca, Alessandra; Roman-Duval, Julia; Roser, Joseph; Roueff, Evelyne; Rouillé, Gaël; Salama, Farid; Sales, Dinalva A.; Sandstrom, Karin; Sarre, Peter; Sciamma-O’Brien, Ella; Sellgren, Kris; Shenoy, Sachindev S.; Teyssier, David; Thomas, Richard D.; Togi, Aditya; Verstraete, Laurent; Witt, Adolf N.; Wootten, Alwyn; Ysard, Nathalie; Zettergren, Henning; Zhang, Yong; Zhang, Ziwei E.; Zhen, JunfengContext. JWST has taken the sharpest and most sensitive infrared (IR) spectral imaging observations ever of the Orion Bar photodis-sociation region (PDR), which is part of the nearest massive star-forming region the Orion Nebula, and often considered to be the ‘prototypical’ strongly illuminated PDR. Aims. We investigate the impact of radiative feedback from massive stars on their natal cloud and focus on the transition from the H II region to the atomic PDR – crossing the ionisation front (IF) –, and the subsequent transition to the molecular PDR – crossing the dissociation front (DF). Given the prevalence of PDRs in the interstellar medium and their dominant contribution to IR radiation, understanding the response of the PDR gas to far-ultraviolet (FUV) photons and the associated physical and chemical processes is fundamental to our understanding of star and planet formation and for the interpretation of any unresolved PDR as seen by JWST. Methods. We used high-resolution near-IR integral field spectroscopic data from NIRSpec on JWST to observe the Orion Bar PDR as part of the PDRs4All JWST Early Release Science programme. We constructed a 3″ × 25″’ spatio-spectral mosaic covering 0.97– 5.27 μm at a spectral resolution R of ~2700 and an angular resolution of 0.075″–0.173″. To study the properties of key regions captured in this mosaic, we extracted five template spectra in apertures centred on the three H2 dissociation fronts, the atomic PDR, and the H II region. This wealth of detailed spatial-spectral information was analysed in terms of variations in the physical conditions-incident UV field, density, and temperature – of the PDR gas. Results. The NIRSpec data reveal a forest of lines including, but not limited to, He I, H I , and C I recombination lines; ionic lines (e.g. Fe III and Fe II); O I and N I fluorescence lines; aromatic infrared bands (AIBs, including aromatic CH, aliphatic CH, and their CD counterparts); pure rotational and ro-vibrational lines from H2; and ro-vibrational lines from HD, CO, and CH+, with most of them having been detected for the first time towards a PDR. Their spatial distribution resolves the H and He ionisation structure in the Huygens region, gives insight into the geometry of the Bar, and confirms the large-scale stratification of PDRs. In addition, we observed numerous smaller-scale structures whose typical size decreases with distance from θ1 Ori C and IR lines from C I , if solely arising from radiative recombination and cascade, reveal very high gas temperatures (a few 1000 K) consistent with the hot irradiated surface of small-scale dense clumps inside the PDR. The morphology of the Bar, in particular that of the H2 lines, reveals multiple prominent filaments that exhibit different characteristics. This leaves the impression of a ‘terraced’ transition from the predominantly atomic surface region to the CO-rich molecular zone deeper in. We attribute the different characteristics of the H2 filaments to their varying depth into the PDR and, in some cases, not reaching the C+/C/CO transition. These observations thus reveal what local conditions are required to drive the physical and chemical processes needed to explain the different characteristics of the DFs and the photochemical evolution of the AIB carriers. Conclusions. This study showcases the discovery space created by JWST to further our understanding of the impact radiation from young stars has on their natal molecular cloud and proto-planetary disk, which touches on star and planet formation as well as galaxy evolution.Item PDRs4All - IV. An embarrassment of riches: Aromatic infrared bands in the Orion Bar(EDP Sciences, 2024) Chown, Ryan; Sidhu, Ameek; Peeters, Els; Tielens, Alexander G. G. M.; Cami, Jan; Berné, Olivier; Habart, Emilie; Alarcón, Felipe; Canin, Amélie; Schroetter, Ilane; Trahin, Boris; Putte, Dries Van De; Abergel, Alain; Bergin, Edwin A.; Bernard-Salas, Jeronimo; Boersma, Christiaan; Bron, Emeric; Cuadrado, Sara; Dartois, Emmanuel; Dicken, Daniel; El-Yajouri, Meriem; Fuente, Asunción; Goicoechea, Javier R.; Gordon, Karl D.; Issa, Lina; Joblin, Christine; Kannavou, Olga; Khan, Baria; Lacinbala, Ozan; Languignon, David; Gal, Romane Le; Maragkoudakis, Alexandros; Meshaka, Raphael; Okada, Yoko; Onaka, Takashi; Pasquini, Sofia; Pound, Marc W.; Robberto, Massimo; Röllig, Markus; Schefter, Bethany; Schirmer, Thiébaut; Vicente, Sílvia; Wolfire, Mark G.; Zannese, Marion; Aleman, Isabel; Allamandola, Louis; Auchettl, Rebecca; Baratta, Giuseppe Antonio; Bejaoui, Salma; Bera, Partha P.; Black, John H.; Boulanger, François; Bouwman, Jordy; Brandl, Bernhard; Brechignac, Philippe; Brünken, Sandra; Buragohain, Mridusmita; Burkhardt, Andrew; Candian, Alessandra; Cazaux, Stéphanie; Cernicharo, Jose; Chabot, Marin; Chakraborty, Shubhadip; Champion, Jason; Colgan, Sean W. J.; Cooke, Ilsa R.; Coutens, Audrey; Cox, Nick L. J.; Demyk, Karine; Meyer, Jennifer Donovan; Foschino, Sacha; García-Lario, Pedro; Gavilan, Lisseth; Gerin, Maryvonne; Gottlieb, Carl A.; Guillard, Pierre; Gusdorf, Antoine; Hartigan, Patrick; He, Jinhua; Herbst, Eric; Hornekaer, Liv; Jäger, Cornelia; Janot-Pacheco, Eduardo; Kaufman, Michael; Kemper, Francisca; Kendrew, Sarah; Kirsanova, Maria S.; Klaassen, Pamela; Kwok, Sun; Labiano, Álvaro; Lai, Thomas S.-Y.; Lee, Timothy J.; Lefloch, Bertrand; Petit, Franck Le; Li, Aigen; Linz, Hendrik; Mackie, Cameron J.; Madden, Suzanne C.; Mascetti, Joëlle; McGuire, Brett A.; Merino, Pablo; Micelotta, Elisabetta R.; Misselt, Karl; Morse, Jon A.; Mulas, Giacomo; Neelamkodan, Naslim; Ohsawa, Ryou; Omont, Alain; Paladini, Roberta; Palumbo, Maria Elisabetta; Pathak, Amit; Pendleton, Yvonne J.; Petrignani, Annemieke; Pino, Thomas; Puga, Elena; Rangwala, Naseem; Rapacioli, Mathias; Ricca, Alessandra; Roman-Duval, Julia; Roser, Joseph; Roueff, Evelyne; Rouillé, Gaël; Salama, Farid; Sales, Dinalva A.; Sandstrom, Karin; Sarre, Peter; Sciamma-O’Brien, Ella; Sellgren, Kris; Shenoy, Sachindev S.; Teyssier, David; Thomas, Richard D.; Togi, Aditya; Verstraete, Laurent; Witt, Adolf N.; Wootten, Alwyn; Zettergren, Henning; Zhang, Yong; Zhang, Ziwei E.; Zhen, JunfengContext. Mid-infrared observations of photodissociation regions (PDRs) are dominated by strong emission features called aromatic infrared bands (AIBs). The most prominent AIBs are found at 3.3, 6.2, 7.7, 8.6, and 11.2 µm. The most sensitive, highest-resolution infrared spectral imaging data ever taken of the prototypical PDR, the Orion Bar, have been captured by JWST. These high-quality data allow for an unprecedentedly detailed view of AIBs.Aims. We provide an inventory of the AIBs found in the Orion Bar, along with mid-IR template spectra from five distinct regions in the Bar: the molecular PDR (i.e. the three H2 dissociation fronts), the atomic PDR, and the H II region. Methods. We used JWST NIRSpec IFU and MIRI MRS observations of the Orion Bar from the JWST Early Release Science Program, PDRs4All (ID: 1288). We extracted five template spectra to represent the morphology and environment of the Orion Bar PDR. We investigated and characterised the AIBs in these template spectra. We describe the variations among them here. Results. The superb sensitivity and the spectral and spatial resolution of these JWST observations reveal many details of the AIB emission and enable an improved characterization of their detailed profile shapes and sub-components. The Orion Bar spectra are dominated by the well-known AIBs at 3.3, 6.2, 7.7, 8.6, 11.2, and 12.7 µm with well-defined profiles. In addition, the spectra display a wealth of weaker features and sub-components. The widths of many AIBs show clear and systematic variations, being narrowest in the atomic PDR template, but showing a clear broadening in the H II region template while the broadest bands are found in the three dissociation front templates. In addition, the relative strengths of AIB (sub-)components vary among the template spectra as well. All AIB profiles are characteristic of class A sources as designated by Peeters (2022, A&A, 390, 1089), except for the 11.2 µm AIB profile deep in the molecular zone, which belongs to class B11.2. Furthermore, the observations show that the sub-components that contribute to the 5.75, 7.7, and 11.2 µm AIBs become much weaker in the PDR surface layers. We attribute this to the presence of small, more labile carriers in the deeper PDR layers that are photolysed away in the harsh radiation field near the surface. The 3.3/11.2 AIB intensity ratio decreases by about 40% between the dissociation fronts and the H II region, indicating a shift in the polycyclic aromatic hydrocarbon (PAH) size distribution to larger PAHs in the PDR surface layers, also likely due to the effects of photochemistry. The observed broadening of the bands in the molecular PDR is consistent with an enhanced importance of smaller PAHs since smaller PAHs attain a higher internal excitation energy at a fixed photon energy. Conclusions. Spectral-imaging observations of the Orion Bar using JWST yield key insights into the photochemical evolution of PAHs, such as the evolution responsible for the shift of 11.2 µm AIB emission from class B11.2 in the molecular PDR to class A11.2 in the PDR surface layers. This photochemical evolution is driven by the increased importance of FUV processing in the PDR surface layers, resulting in a “weeding out” of the weakest links of the PAH family in these layers. For now, these JWST observations are consistent with a model in which the underlying PAH family is composed of a few species: the so-called ‘grandPAHs’.Item PDRs4All - VI. Probing the photochemical evolution of PAHs in the Orion Bar using machine learning techniques(EDP Sciences, 2024) Pasquini, Sofia; Peeters, Els; Schefter, Bethany; Khan, Baria; Sidhu, Ameek; Chown, Ryan; Cami, Jan; Tielens, Alexander; Alarcón, Felipe; Canin, Amélie; Schroetter, Ilane; Trahin, Boris; Putte, Dries Van De; Boersma, Christiaan; Dartois, Emmanuel; Onaka, Takashi; Candian, Alessandra; Hartigan, Patrick; Lai, Thomas S.-Y.; Rouillé, Gaël; Sales, Dinalva A.; Zhang, Yong; Bernard-Salas, Jeronimo; Habart, Emilie; Berné, OlivierContext. Extraordinary observations of the Orion Bar by JWST have shown, for the first time, the incredible richness of polycyclic aromatic hydrocarbon (PAH) emission bands and their variation on very small scales. These variations are the result of photochemical evolution of the PAH carrier.Aims. We aim to probe the photochemical evolution of PAHs across the key zones of the ideal photodissociation region (PDR) that is the Orion Bar using unsupervised machine learning. Methods. We used JWST NIRSpec IFU and MIRI MRS observations of the Orion Bar from the JWST Early Release Science programme PDRs4All (ID: 1288). We levered bisecting k-means clustering to generate highly detailed spatial maps of the spectral variability in the 3.2–3.6, 5.95–6.6, 7.25–8.95, and 10.9–11.63 μm wavelength regions. We analysed and subsequently described the variations in the cluster profiles and connected them to the conditions of the physical locations from which they arise. We interpreted the origin of the observed variations with respect to the following key zones: the H II region, the atomic PDR zone, and the layers of the molecular PDR zone stratified by the first, second, and third dissociation fronts (DF 1, DF 2, and DF 3, respectively). Results. Observed PAH emission exhibits spectral variation that is highly dependent on the spatial position in the PDR. We find the 8.6 μm band to behave differently than all other bands, which vary systematically with one another. Notably, we find a uniform variation in the 3.4–3.6 μm bands and 3.4/3.3 intensity ratio. We attribute the carrier of the 3.4–3.6 μm bands to a single side group attached to very similarly sized PAHs. Further, cluster profiles reveal a transition between characteristic profile classes of the 11.2 μm feature from the atomic to the molecular PDR zones. We find the carriers of each of the profile classes to be independent, and reason the latter to be PAH clusters existing solely deep in the molecular PDR. Clustering also reveals a connection between the 11 .2 and 6.2 μm bands and that clusters generated from variation in the 10.9–11.63 μm region can be used to recover those in the 5.95–6.6 μm region. Conclusions. Clustering is a powerful and comprehensive tool for characterising PAH spectral variability on both spatial and spectral scales. For individual bands as well as global spectral behaviours, we find ultraviolet processing to be the most important driver of the evolution of PAHs and their spectral signatures in the Orion Bar PDR.Item PDRs4All - VIII. Mid-infrared emission line inventory of the Orion Bar(EDP Sciences, 2024) Putte, Dries Van De; Meshaka, Raphael; Trahin, Boris; Habart, Emilie; Peeters, Els; Berné, Olivier; Alarcón, Felipe; Canin, Amélie; Chown, Ryan; Schroetter, Ilane; Sidhu, Ameek; Boersma, Christiaan; Bron, Emeric; Dartois, Emmanuel; Goicoechea, Javier R.; Gordon, Karl D.; Onaka, Takashi; Tielens, Alexander G. G. M.; Verstraete, Laurent; Wolfire, Mark G.; Abergel, Alain; Bergin, Edwin A.; Bernard-Salas, Jeronimo; Cami, Jan; Cuadrado, Sara; Dicken, Daniel; Elyajouri, Meriem; Fuente, Asunción; Joblin, Christine; Khan, Baria; Lacinbala, Ozan; Languignon, David; Gal, Romane Le; Maragkoudakis, Alexandros; Okada, Yoko; Pasquini, Sofia; Pound, Marc W.; Robberto, Massimo; Röllig, Markus; Schefter, Bethany; Schirmer, Thiébaut; Tabone, Benoit; Vicente, Sílvia; Zannese, Marion; Colgan, Sean W. J.; He, Jinhua; Rouillé, Gaël; Togi, Aditya; Aleman, Isabel; Auchettl, Rebecca; Baratta, Giuseppe Antonio; Bejaoui, Salma; Bera, Partha P.; Black, John H.; Boulanger, Francois; Bouwman, Jordy; Brandl, Bernhard; Brechignac, Philippe; Brünken, Sandra; Buragohain, Mridusmita; Burkhardt, Andrew; Candian, Alessandra; Cazaux, Stéphanie; Cernicharo, Jose; Chabot, Marin; Chakraborty, Shubhadip; Champion, Jason; Cooke, Ilsa R.; Coutens, Audrey; Cox, Nick L. J.; Demyk, Karine; Meyer, Jennifer Donovan; Foschino, Sacha; García-Lario, Pedro; Gerin, Maryvonne; Gottlieb, Carl A.; Guillard, Pierre; Gusdorf, Antoine; Hartigan, Patrick; Herbst, Eric; Hornekaer, Liv; Issa, Lina; Jäger, Cornelia; Janot-Pacheco, Eduardo; Kannavou, Olga; Kaufman, Michael; Kemper, Francisca; Kendrew, Sarah; Kirsanova, Maria S.; Klaassen, Pamela; Kwok, Sun; Labiano, Álvaro; Lai, Thomas S.-Y.; Floch, Bertrand Le; Petit, Franck Le; Li, Aigen; Linz, Hendrik; Mackie, Cameron J.; Madden, Suzanne C.; Mascetti, Joëlle; McGuire, Brett A.; Merino, Pablo; Micelotta, Elisabetta R.; Morse, Jon A.; Mulas, Giacomo; Neelamkodan, Naslim; Ohsawa, Ryou; Omont, Alain; Paladini, Roberta; Palumbo, Maria Elisabetta; Pathak, Amit; Pendleton, Yvonne J.; Petrignani, Annemieke; Pino, Thomas; Puga, Elena; Rangwala, Naseem; Rapacioli, Mathias; Rho, Jeonghee; Ricca, Alessandra; Roman-Duval, Julia; Roser, Joseph; Roueff, Evelyne; Salama, Farid; Sales, Dinalva A.; Sandstrom, Karin; Sarre, Peter; Sciamma-O’Brien, Ella; Sellgren, Kris; Shenoy, Sachindev S.; Teyssier, David; Thomas, Richard D.; Witt, Adolf N.; Wootten, Alwyn; Ysard, Nathalie; Zettergren, Henning; Zhang, Yong; Zhang, Ziwei E.; Zhen, JunfengContext. Mid-infrared emission features are important probes of the properties of ionized gas and hot or warm molecular gas, which are difficult to probe at other wavelengths. The Orion Bar photodissociation region (PDR) is a bright, nearby, and frequently studied target containing large amounts of gas under these conditions. Under the “PDRs4All” Early Release Science Program for JWST, a part of the Orion Bar was observed with MIRI integral field unit (IFU) spectroscopy, and these high-sensitivity IR spectroscopic images of very high angular resolution (0.2″) provide a rich observational inventory of the mid-infrared (MIR) emission lines, while resolving the H II region, the ionization front, and multiple dissociation fronts. Aims. We list, identify, and measure the most prominent gas emission lines in the Orion Bar using the new MIRI IFU data. An initial analysis summarizes the physical conditions of the gas and demonstrates the potential of these new data and future IFU observations with JWST. Methods. The MIRI IFU mosaic spatially resolves the substructure of the PDR, its footprint cutting perpendicularly across the ionization front and three dissociation fronts. We performed an up-to-date data reduction, and extracted five spectra that represent the ionized, atomic, and molecular gas layers. We identified the observed lines through a comparison with theoretical line lists derived from atomic data and simulated PDR models. The identified species and transitions are summarized in the main table of this work, with measurements of the line intensities and central wavelengths. Results. We identified around 100 lines and report an additional 18 lines that remain unidentified. The majority consists of H I recombination lines arising from the ionized gas layer bordering the PDR. The H I line ratios are well matched by emissivity coefficients from H recombination theory, but deviate by up to 10% because of contamination by He I lines. We report the observed emission lines of various ionization stages of Ne, P, S, Cl, Ar, Fe, and Ni. We show how the Ne III/Ne II, S IV/S III, and Ar III/Ar II ratios trace the conditions in the ionized layer bordering the PDR, while Fe III/Fe II and Ni III/Ni II exhibit a different behavior, as there are significant contributions to Fe II and Ni II from the neutral PDR gas. We observe the pure-rotational H2 lines in the vibrational ground state from 0–0 S(1) to 0–0 S (8), and in the first vibrationally excited state from 1–1 S (5) to 1–1 S(9). We derive H2 excitation diagrams, and for the three observed dissociation fronts, the rotational excitation can be approximated with one thermal (~700 K) component representative of an average gas temperature, and one nonthermal component (~2700 K) probing the effect of UV pumping. We compare these results to an existing model of the Orion Bar PDR, and find that the predicted excitation matches the data qualitatively, while adjustments to the parameters of the PDR model are required to reproduce the intensity of the 0–0 S (6) to S (8) lines.Item Probing Jets from Young Embedded Sources: Clues from HST Near-IR [Fe ii] Images(IOP Publishing, 2021) Erkal, Jessica; Nisini, Brunella; Coffey, Deirdre; Bacciotti, Francesca; Hartigan, Patrick; Antoniucci, Simone; Giannini, Teresa; Eislöffel, Jochen; Manara, Carlo FeliceWe present near-infrared [Fe ii] images of four Class 0/I jets (HH 1/2, HH 34, HH 111, HH 46/47) observed with the Hubble Space Telescope (HST) Wide Field Camera 3. The unprecedented angular resolution allows us to measure proper motions, jet widths and trajectories, and extinction along the jets. In all cases, we detect the counterjet, which was barely visible or invisible at shorter wavelengths. We measure tangential velocities of a few hundred kilometers per second, consistent with previous HST measurements over 10 years ago. We measure the jet width as close as a few tens of au from the star, revealing high collimations of about 2° for HH 1, HH 34, and HH 111 and about 8° for HH 46, all of which are preserved up to large distances. For HH 34, we find evidence of a larger initial opening angle of about 7°. Measurement of knot positions reveals deviations in trajectory of both the jet and counterjet of all sources. Analysis of asymmetries in the inner knot positions for HH 111 suggests the presence of a low mass stellar companion at separation 20–30 au. Finally, we find extinction values of 15–20 mag near the source, which gradually decrease moving downstream along the jet. These observations have allowed us to study the counterjet at unprecedentedly high angular resolution and will be a valuable reference for planning future JWST mid-infrared observations that will peer even closer into the jet engine.Item PROJECT-J: JWST Observations of HH46 IRS and Its Outflow. Overview and First Results(IOP Publishing, 2024) Nisini, Brunella; Navarro, Maria Gabriela; Giannini, Teresa; Antoniucci, Simone; Patrick, J. Kavanagh; Hartigan, Patrick; Bacciotti, Francesca; Garatti, Alessio Caratti o; Noriega-Crespo, Alberto; Dishoeck, Ewine F. van; Whelan, Emma T.; Arce, Hector G.; Cabrit, Sylvie; Coffey, Deirdre; Fedele, Davide; Eislöffel, Jochen; Palumbo, Maria Elisabetta; Podio, Linda; Ray, Tom P.; Schultze, Megan; Urso, Riccardo G.; Alcalá, Juan M.; Bautista, Manuel A.; Codella, Claudio; Greene, Thomas P.; Manara, Carlo F.We present the first results of the JWST program PROJECT-J (PROtostellar JEts Cradle Tested with JWST), designed to study the Class I source HH46 IRS and its outflow through NIRSpec and MIRI spectroscopy (1.66–28 μm). The data provide line images (∼6.″6 in length with NIRSpec, and up to ∼20″ with MIRI) revealing unprecedented details within the jet, the molecular outflow, and the cavity. We detect, for the first time, the redshifted jet within ∼90 au from the source. Dozens of shock-excited forbidden lines are observed, including highly ionized species such as [Ne iii] 15.5 μm, suggesting that the gas is excited by high velocity (>80 km s−1) shocks in a relatively high-density medium. Images of H2 lines at different excitations outline a complex molecular flow, where a bright cavity, molecular shells, and a jet-driven bow shock interact with and are shaped by the ambient conditions. Additional NIRCam 2 μm images resolve the HH46 IRS ∼110 au binary system and suggest that the large asymmetries observed between the jet and the H2 wide-angle emission could be due to two separate outflows being driven by the two sources. The spectra of the unresolved binary show deep ice bands and plenty of gaseous lines in absorption, likely originating in a cold envelope or disk. In conclusion, JWST has unraveled for the first time the origin of the HH46 IRS complex outflow demonstrating its capability to investigate embedded regions around young stars, which remain elusive even at near-IR wavelengths.Item Rubin Observatory LSST Transients and Variable Stars Roadmap(IOP Publishing Ltd, 2023) Hambleton, Kelly M.; Bianco, Federica B.; Street, Rachel; Bell, Keaton; Buckley, David; Graham, Melissa; Hernitschek, Nina; Lund, Michael B.; Mason, Elena; Pepper, Joshua; Prša, Andrej; Rabus, Markus; Raiteri, Claudia M.; Szabó, Róbert; Szkody, Paula; Andreoni, Igor; Antoniucci, Simone; Balmaverde, Barbara; Bellm, Eric; Bonito, Rosaria; Bono, Giuseppe; Botticella, Maria Teresa; Brocato, Enzo; Bricman, Katja Bučar; Cappellaro, Enrico; Carnerero, Maria Isabel; Chornock, Ryan; Clarke, Riley; Cowperthwaite, Phil; Cucchiara, Antonino; D’Ammando, Filippo; Dage, Kristen C.; Dall’Ora, Massimo; Davenport, James R. A.; Martino, Domitilla de; Somma, Giulia de; Criscienzo, Marcella Di; Stefano, Rosanne Di; Drout, Maria; Fabrizio, Michele; Fiorentino, Giuliana; Gandhi, Poshak; Garofalo, Alessia; Giannini, Teresa; Gomboc, Andreja; Greggio, Laura; Hartigan, Patrick; Hundertmark, Markus; Johnson, Elizabeth; Johnson, Michael; Jurkic, Tomislav; Khakpash, Somayeh; Leccia, Silvio; Li, Xiaolong; Magurno, Davide; Malanchev, Konstantin; Marconi, Marcella; Margutti, Raffaella; Marinoni, Silvia; Mauron, Nicolas; Molinaro, Roberto; Möller, Anais; Moniez, Marc; Muraveva, Tatiana; Musella, Ilaria; Ngeow, Chow-Choong; Pastorello, Andrea; Petrecca, Vincenzo; Piranomonte, Silvia; Ragosta, Fabio; Reguitti, Andrea; Righi, Chiara; Ripepi, Vincenzo; Sandoval, Liliana Rivera; Stassun, Keivan G.; Stroh, Michael; Terreran, Giacomo; Trimble, Virginia; Tsapras, Yiannis; Velzen, Sjoert van; Venuti, Laura; Vink, Jorick S.The Vera C. Rubin Legacy Survey of Space and Time (LSST) holds the potential to revolutionize time domain astrophysics, reaching completely unexplored areas of the Universe and mapping variability time scales from minutes to a decade. To prepare to maximize the potential of the Rubin LSST data for the exploration of the transient and variable Universe, one of the four pillars of Rubin LSST science, the Transient and Variable Stars Science Collaboration, one of the eight Rubin LSST Science Collaborations, has identified research areas of interest and requirements, and paths to enable them. While our roadmap is ever-evolving, this document represents a snapshot of our plans and preparatory work in the final years and months leading up to the survey’s first light.Item SpinSpotter : An Automated Algorithm for Identifying Stellar Rotation Periods with Autocorrelation Analysis(IOP Publishing, 2022) Holcomb, Rae J.; Robertson, Paul; Hartigan, Patrick; Oelkers, Ryan J.; Robinson, CalebSpinSpotter is a robust and automated algorithm designed to extract stellar rotation periods from large photometric data sets with minimal supervision. Our approach uses the autocorrelation function (ACF) to identify stellar rotation periods up to one-third the observational baseline of the data. Our algorithm also provides a suite of diagnostics that describe the features in the ACF, which allows the user to fine-tune the tolerance with which to accept a period detection. We apply it to approximately 130,000 main-sequence stars observed by the Transiting Exoplanet Survey Satellite at 2-minute cadence during Sectors 1–26 and identify rotation periods for 13,504 stars ranging from 0.4 to 14 days. We demonstrate good agreement between our sample and known values from the literature and note key differences between our population of rotators and those previously identified in the Kepler field, most notably a large population of fast-rotating M dwarfs. Our sample of rotating stars provides a data set with coverage of nearly the entire sky that can be used as a basis for future gyrochronological studies and, when combined with proper motions and distances from Gaia, to search for regions with high densities of young stars, thus identifying areas of recent star formation and undiscovered moving group members. Our algorithm is publicly available for download and use on GitHub at https://github.com/rae-holcomb/SpinSpotter.Item Using the ROSS optical streak camera as a tool to understand laboratory experiments of laser-driven magnetized shock waves(Cambridge University Press, 2018) Liao, Andy; Hartigan, Patrick; Fiksel, Gennady; Blue, Brent; Graham, Peter; Foster, John; Kuranz, CarolynSupersonic flows with high Mach number are ubiquitous in astrophysics. High-powered lasers also have the ability to drive high Mach number, radiating shock waves in laboratory plasmas, and recent experiments along these lines have made it possible to recreate analogs of high Mach-number astrophysical flows under controlled conditions. Streak cameras such as the Rochester optical streak system (ROSS) are particularly helpful in diagnosing such experiments, because they acquire spatially resolved measurements of the radiating gas continuously over a large time interval, making it easy to observe how any shock waves and ablation fronts present in the system evolve with time. This paper summarizes new ROSS observations of a laboratory analog of the collision of a stellar wind with an ablating planetary atmosphere embedded within a magnetosphere. We find good agreement between the observed ROSS data and numerical models obtained with the FLASH code, but only when the effects of optical depth are properly taken into account.