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Related papers: The TEXES Survey For H2 Emission From Protoplaneta…

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We present an analysis of Spitzer-IRS spectroscopic maps of the L1157 protostellar outflow in the H2 pure-rotational lines from S(0) to S(7). The aim of this work is to derive the physical conditions pertaining to the warm molecular gas and…

Solar and Stellar Astrophysics · Physics 2015-05-20 B. Nisini , T. Giannini , D. A. Neufeld , Y. Yuan , S. Antoniucci , E. A. Bergin , G. J. Melnick

We examined variations in the 160/250 and 250/350 micron surface brightness ratios within 24 nearby (<30 Mpc) face-on spiral galaxies observed with the Herschel Space Observatory to identify the heating mechanisms for dust emitting at these…

(Abridged) Far-infrared Herschel-PACS spectra of 18 low-mass protostars of various luminosities and evolutionary stages are studied. We quantify their far-infrared line emission and the contribution of different atomic and molecular species…

We have obtained sub-arcsec mid-IR images of a sample of debris disks within 100 pc. For our sample of nineteen A-type debris disk candidates chosen for their IR excess, we have resolved, for the first time, five sources plus the previously…

Solar and Stellar Astrophysics · Physics 2015-03-17 Margaret Moerchen , Charles Telesco , Christopher Packham

We present the largest survey of spectrally resolved mid-infrared water emission to date, with spectra for 11 disks obtained with the Michelle and TEXES spectrographs on Gemini North. Water emission is detected in 6 of 8 disks around…

Solar and Stellar Astrophysics · Physics 2019-03-27 Colette Salyk , John Lacy , Matt Richter , Ke Zhang , Klaus Pontoppidan , John S. Carr , Joan R. Najita , Geoffrey A. Blake

CO is an important component of a protoplanetary disc as it is one of the most abundant gas phase species. Furthermore, observations of the CO transitions can be used as a diagnostic of the gas, tracing conditions in both the inner and…

We present X-ray spectral analysis of the accreting young star TW Hydrae from a 489 ks observation using the Chandra High Energy Transmission Grating. The spectrum provides a rich set of diagnostics for electron temperature T_e, electron…

Solar and Stellar Astrophysics · Physics 2015-05-14 N. S. Brickhouse , S. R. Cranmer , A. K. Dupree , G. J. M. Luna , S. Wolk

Using HST-COS FUV spectra, we have discovered warm molecular hydrogen in the TWA 7 system. TWA 7, a $\sim$9 Myr old M2.5 star, has a cold debris disk and has previously shown no signs of accretion. Molecular hydrogen is expected to be…

Solar and Stellar Astrophysics · Physics 2021-11-17 Laura Flagg , Christopher Johns-Krull , Kevin France , Gregory Herczeg , Joan Najita , John Carptenter , Scott J. Kenyon

We report infrared spectroscopic observations of HD 105, a nearby ($\sim 40$ pc) and relatively young ($\sim 30$ Myr) G0 star with excess infrared continuum emission, which has been modeled as arising from an optically thin circumstellar…

A classical paradox in high-mass star formation is that powerful radiation pressure can halt accretion, preventing further growth of a central star. Disk accretion has been proposed to solve this problem, but the disks and the accretion…

We compare line emission calculated from theoretical disk models with optical to sub-millimeter wavelength observational data of the gas disk surrounding TW Hya and infer the spatial distribution of mass in the gas disk. The model disk that…

Earth and Planetary Astrophysics · Physics 2015-05-28 Uma Gorti , David Hollenbach , Joan Najita , Ilaria Pascucci

We present the results of a search for pure rotational molecular hydrogen emission from two pre-main-sequence stars, AB Aur and CQ Tau. Observations were made using MICHELLE, the mid-IR echelle spectrometer at the UK Infrared Telescope. We…

Astrophysics · Physics 2009-11-07 I. Sheret , S. K. Ramsay Howat , W. R. F. Dent

We analyze the far-ultraviolet (FUV) spectra of 33 classical T Tauri stars (CTTS), including 20 new spectra obtained with the Advanced Camera for Surveys Solar Blind Channel (ACS/SBC) on the Hubble Space Telescope. Of the sources, 28 are in…

I present here the summary of results from a survey by De Buizer (2003) searching for outflows using near-infrared imaging. Targets were massive young stellar objects associated with methanol masers in linear distributions. Presently, it is…

Astrophysics · Physics 2007-05-23 James M. De Buizer

The relative abundances of atomic and molecular species in planet-forming disks around young stars provide important constraints on photochemical disk models and provide a baseline for calculating disk masses from measurements of trace…

Solar and Stellar Astrophysics · Physics 2015-06-22 Kevin France , Gregory J. Herczeg , Matthew McJunkin , Steven V. Penton

We present far-IR (57-196 mu) spectra of 21 protostars in the Orion molecular clouds, obtained with the Photodetector Array Camera and Spectrometer (PACS) onboard the Herschel Space observatory, as part of the Herschel Orion Protostar…

Massive stars play an important role in many areas of astrophysics, but numerous details regarding their formation remain unclear. In this paper we present and analyse high resolution (R ~ 30,000) near-infrared 2.3 micron spectra of 20…

Measurements of molecular hydrogen (H_2) column densities are presented for the first six rotational levels (J=0 to 5) for 73 extragalactic targets observed with FUSE. All of these have a final signal-to-noise ratio larger than \snlimit,…

Astrophysics · Physics 2009-11-11 B. P. Wakker

Measuring the temperature and abundance patterns of clouds in the interstellar medium (ISM) provides an observational basis for models of the physical conditions within the clouds, which play an important role in studies of star and planet…

Astrophysics of Galaxies · Physics 2019-06-26 Nicholas Kruczek , Kevin France , Keri Hoadley , Brian Fleming , Nicholas Nell
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