Browsing by Author "Manara, Carlo F."

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    A Magnetically Driven Disk Wind in the Inner Disk of PDS 70*
    (IOP Publishing Ltd, 2023) Campbell-White, Justyn; Manara, Carlo F.; Benisty, Myriam; Natta, Antonella; Claes, Rik A. B.; Frasca, Antonio; Bae, Jaehan; Facchini, Stefano; Isella, Andrea; Pérez, Laura; Pinilla, Paola; Sicilia-Aguilar, Aurora; Teague, Richard
    PDS 70 is so far the only young disk where multiple planets have been detected by direct imaging. The disk has a large cavity when seen at submillimeter and near-infrared wavelengths, which hosts two massive planets. This makes PDS 70 the ideal target to study the physical conditions in a strongly depleted inner disk shaped by two giant planets, and in particular to test whether disk winds can play a significant role in its evolution. Using X-Shooter and HARPS spectra, we detected for the first time the wind-tracing [O i] 6300 Å line, and confirm the low-moderate value of mass-accretion rate in the literature. The [O i] line luminosity is high with respect to the accretion luminosity when compared to a large sample of disks with cavities in nearby star-forming regions. The FWHM and blueshifted peak of the [O i] line suggest an emission in a region very close to the star, favoring a magnetically driven wind as the origin. We also detect wind emission and high variability in the He i 10830 Å line, which is unusual for low accretors. We discuss that, although the cavity of PDS 70 was clearly carved out by the giant planets, the substantial inner-disk wind could also have had a significant contribution to clearing the inner disk.
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    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.
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    Ringed Structures of the HD 163296 Protoplanetary Disk Revealed by ALMA
    (American Physical Society, 2016) Isella, Andrea; Guidi, Greta; Testi, Leonardo; Liu, Shangfei; Li, Hui; Li, Shengtai; Weaver, Erik; Boehler, Yann; Carperter, John M.; De Gregorio-Monsalvo, Itziar; Manara, Carlo F.; Natta, Antonella; Pérez, Laura M.; Ricci, Luca; Sargent, Anneila; Tazzari, Marco; Turner, Neal
    We present Atacama Large Millimeter and Submillimeter Array observations of the protoplanetary disk around the Herbig Ae star HD 163296 that trace the spatial distribution of millimeter-sized particles and cold molecular gas on spatial scales as small as 25 astronomical units (A.U.). The image of the disk recorded in the 1.3 mm continuum emission reveals three dark concentric rings that indicate the presence of dust depleted gaps at about 60, 100, and 160 A.U. from the central star. The maps of the 12CO, 13CO, and C18O J=2−1 emission do not show such structures but reveal a change in the slope of the radial intensity profile across the positions of the dark rings in the continuum image. By comparing the observations with theoretical models for the disk emission, we find that the density of CO molecules is reduced inside the middle and outer dust gaps. However, in the inner ring there is no evidence of CO depletion. From the measurements of the dust and gas densities, we deduce that the gas-to-dust ratio varies across the disk and, in particular, it increases by at least a factor 5 within the inner dust gap compared to adjacent regions of the disk. The depletion of both dust and gas suggests that the middle and outer rings could be due to the gravitational torque exerted by two Saturn-mass planets orbiting at 100 and 160 A.U. from the star. On the other hand, the inner dust gap could result from dust accumulation at the edge of a magnetorotational instability dead zone, or from dust opacity variations at the edge of the CO frost line. Observations of the dust emission at higher angular resolution and of molecules that probe dense gas are required to establish more precisely the origins of the dark rings observed in the HD 163296 disk.
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    The population of young low-mass stars in Trumpler 14
    (edp Sciences, 2024) Itrich, Dominika; Testi, Leonardo; Beccari, Giacomo; Manara, Carlo F.; Reiter, Megan; Preibisch, Thomas; McLeod, Anna F.; Rosotti, Giovanni; Klessen, Ralf; Molinari, Sergio; Hennebelle, Patrick
    Massive star-forming regions are thought to be the most common birth environments in the Galaxy and the only birth places of very massive stars. Their presence in the stellar cluster alters the conditions within the cluster, impacting at the same time the evolution of other cluster members. In principle, copious amounts of ultraviolet radiation produced by massive stars can remove material from outer parts of the protoplanetary discs around low- and intermediate-mass stars in the process of external photoevaporation, effectively reducing the planet formation capabilities of those discs. Here, we present deep VLT/MUSE observations of low-mass stars in Trumpler 14, one of the most massive, young, and compact clusters in the Carina Nebula Complex. We provide spectral and stellar properties of 717 sources and based on the distribution of stellar ages, derive the cluster age of ∼1 Myr. The majority of the stars in our sample have masses ≤1 M⊙, which makes our spectroscopic catalogue the deepest to date in term of mass and proves that detailed investigations of low-mass stars are possible in the massive but distant regions. Spectroscopic studies of low-mass members of the whole Carina Nebula Complex are missing. Our work marks an important step forward towards filling this gap and sets the stage for follow-up investigations of accretion properties in Trumpler 14.
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    Twenty-five Years of Accretion onto the Classical T Tauri Star TW Hya
    (IOP Publishing Ltd, 2023) Herczeg, Gregory J.; Chen, Yuguang; Donati, Jean-Francois; Dupree, Andrea K.; Walter, Frederick M.; Hillenbrand, Lynne A.; Johns-Krull, Christopher M.; Manara, Carlo F.; Günther, Hans Moritz; Fang, Min; Schneider, P. Christian; Valenti, Jeff A.; Alencar, Silvia H. P.; Venuti, Laura; Alcalá, Juan Manuel; Frasca, Antonio; Arulanantham, Nicole; Linsky, Jeffrey L.; Bouvier, Jerome; Brickhouse, Nancy S.; Calvet, Nuria; Espaillat, Catherine C.; Campbell-White, Justyn; Carpenter, John M.; Chang, Seok-Jun; Cruz, Kelle L.; Dahm, S. E.; Eislöffel, Jochen; Edwards, Suzan; Fischer, William J.; Guo, Zhen; Henning, Thomas; Ji, Tao; Jose, Jessy; Kastner, Joel H.; Launhardt, Ralf; Principe, David A.; Robinson, Connor E.; Serna, Javier; Siwak, Michal; Sterzik, Michael F.; Takasao, Shinsuke
    Accretion plays a central role in the physics that governs the evolution and dispersal of protoplanetary disks. The primary goal of this paper is to analyze the stability over time of the mass accretion rate onto TW Hya, the nearest accreting solar-mass young star. We measure veiling across the optical spectrum in 1169 archival high-resolution spectra of TW Hya, obtained from 1998–2022. The veiling is then converted to accretion rate using 26 flux-calibrated spectra that cover the Balmer jump. The accretion rate measured from the excess continuum has an average of 2.51 × 10−9 M ⊙ yr−1 and a Gaussian distribution with an FWHM of 0.22 dex. This accretion rate may be underestimated by a factor of up to 1.5 because of uncertainty in the bolometric correction and another factor of 1.7 because of excluding the fraction of accretion energy that escapes in lines, especially Lyα. The accretion luminosities are well correlated with He line luminosities but poorly correlated with Hα and Hβ luminosity. The accretion rate is always flickering over hours but on longer timescales has been stable over 25 years. This level of variability is consistent with previous measurements for most, but not all, accreting young stars.