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相关论文: A High Resolution Study of the HI-H2 Transition ac…

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We use the Sternberg et al. (2014) theory for interstellar atomic to molecular (HI-to-H$_2$) conversion to analyze HI-to-H$_2$ transitions in five (low-mass) star-forming and dark regions in the Perseus molecular cloud, B1, B1E, B5, IC348,…

星系天体物理 · 物理学 2015-08-17 Shmuel Bialy , Amiel Sternberg , Min-Young Lee , Franck Le Petit , Evelyne Roueff

We investigate the impact of high optical depth on the HI saturation observed in the Perseus molecular cloud by using Arecibo HI emission and absorption measurements toward 26 radio continuum sources. The spin temperature and optical depth…

星系天体物理 · 物理学 2015-08-19 Min-Young Lee , Snezana Stanimirovic , Claire E. Murray , Carl Heiles , Jesse Miller

We derive the CO-to-H2 conversion factor, X_CO = N(H2)/I_CO, across the Perseus molecular cloud on sub-parsec scales by combining the dust-based N(H2) data with the I_CO data from the COMPLETE Survey. We estimate an average X_CO ~ 3 x 10^19…

We apply the Sternberg et al. (2014) theoretical model to analyze HI and H2 observations in the Perseus molecular cloud. We constrain the physical properties of the HI shielding envelopes and the nature of the HI-to-H2 transitions. Our…

星系天体物理 · 物理学 2016-06-01 Shmuel Bialy , Amiel Sternberg , Min-Young Lee , Franck Le Petit , Evelyne Roueff

We derive two-dimensional spatial power spectra of four distinct interstellar medium tracers, HI, $^{12}$CO($J$=1--0), $^{13}$CO($J$=1--0), and dust, in the Perseus molecular cloud, covering linear scales ranging from $\sim$0.1 pc to…

星系天体物理 · 物理学 2018-04-18 Nickolas Pingel , Min-Young Lee , Blakesley Burkhart , Snezana Stanimirović

Comparison analyses between the gas emission data (HI 21cm line and CO 2.6 mm line) and the Planck/IRAS dust emission data (optical depth at 353 GHz tau353 and dust temperature Td) allow us to estimate the amount and distribution of the…

星系天体物理 · 物理学 2017-04-12 Ryuji Okamoto , Hiroaki Yamamoto , Kengo Tachihara , Takahiro Hayakawa , Katsuhiro Hayashi , Yasuo Fukui

We have observed 12CO J = 2-1 and J = 1-0, and 13CO J = 1-0 emission in two regions of HI Self-Absorption (HISA) in Perseus: a small, isolated HISA feature called the globule and a more extended HISA cloud called the complex. Using both…

天体物理学 · 物理学 2009-11-13 P. D. Klaassen , R. Plume , S. J. Gibson , A. R. Taylor , C. M. Brunt

We study the effect of density fluctuations induced by turbulence on the HI/H$_2$ structure in photodissociation regions (PDRs) both analytically and numerically. We perform magnetohydrodynamic numerical simulations for both subsonic and…

星系天体物理 · 物理学 2017-07-26 Shmuel Bialy , Blakesley Burkhart , Amiel Sternberg

In recent decades, significant attention has been dedicated to analytical and observational studies of the atomic hydrogen (HI) to molecular hydrogen (H2) transition in the interstellar medium. We focussed on the Draco diffuse cloud to gain…

We present a survey of the Perseus molecular cloud in the J $=$ 1$\rightarrow$0 transition of HCN, a widely used tracer of dense molecular gas. The survey was conducted with the CfA 1.2 m telescope, which at 89 GHz has a beam width of 11'…

星系天体物理 · 物理学 2023-03-08 T. M. Dame , Charles J. Lada

The Perseus molecular cloud complex is a ~30pc long chain of molecular clouds most well-known for the two star-forming clusters NGC1333 and IC348 and the well-studied outflow source in B5. However, when studied at mid- to far-infrared…

天体物理学 · 物理学 2009-11-11 Naomi A. Ridge , Scott L. Schnee , Alyssa A. Goodman , Jonathan B. Foster

We present the first results on the diffuse transition clouds observed in [CII] line emission at 158 microns (1.9 THz) towards Galactic longitudes near 340deg (5 LOSs) and 20deg (11 LOSs) as part of the GOT C+ survey. Out of the total 146…

星系天体物理 · 物理学 2015-05-19 T. Velusamy , W. D. Langer , J. L. Pineda , P. F. Goldsmith , D. Li. , H. W. Yorke

We present optical depth and temperature maps of the Perseus molecular cloud, obtained combining dust emission data from the Herschel and Planck satellites and 2MASS/NIR dust extinction maps. The maps have a resolution of 36 arcsec in the…

太阳与恒星天体物理 · 物理学 2016-03-02 E. Zari , M. Lombardi , J. Alves , C. J. Lada , H. Bouy

We present observations of velocity-resolved [CII] 158 $\mu$m emission from both a dense and a more diffuse photodissociation region (PDR) in the Perseus giant molecular cloud (GMC) using the Heterodyne Instrument for the Far-Infrared…

星系天体物理 · 物理学 2020-08-19 K. P. Hall , Snežana Stanimirović , Min-Young Lee , Mark Wolfire , Paul Goldsmith

ABRIDGED: Context: HI and CO large scale surveys of the Milky Way trace the diffuse atomic clouds and the dense shielded regions of molecular hydrogen clouds. However, until recently, we have not had spectrally resolved C+ surveys to…

星系天体物理 · 物理学 2015-06-18 W. D. Langer , T. Velusamy , J. L. Pineda , K. Willacy , P. F. Goldsmith

We have investigated the time scale for formation of molecular clouds by examining the conversion of HI to H2 using a time-dependent model. H2 formation on dust grains and cosmic ray and photo destruction are included in one-dimensional…

天体物理学 · 物理学 2008-11-26 Paul F. Goldsmith , Di Li , Marko Krco

The majority of hydrogen in the interstellar medium (ISM) is in atomic form. The transition from atoms to molecules and, in particular, the formation of the H$_2$ molecule, is a key step in cosmic structure formation en route to stars.…

星系天体物理 · 物理学 2018-10-31 Pei Zuo , Di Li , J. E. G. Peek , Qiang Chang , Xia Zhang , Nicholas chapman , Paul F. Goldsmith , Zhi-Yu Zhang

The shape of the probability distribution function (PDF) of molecular clouds is an important ingredient for modern theories of star formation and turbulence. Recently, several studies have pointed out observational difficulties with…

星系天体物理 · 物理学 2015-10-07 Blakesley Burkhart , Min-Young Lee , Claire Murray , Snezana Stanimirovic

We present the discovery of a molecular cloud at zabs=2.5255 along the line of sight to the quasar J0000+0048. We perform a detailed analysis of the absorption lines from ionic, neutral atomic and molecular species in different excitation…

Molecular hydrogen (H2) is the main constituent of the gas in the planet-forming disks that surround many PMS stars. H2 can be incorporated in the atmosphere of the giant planets. HD has been detected in a few disks and can be considered…

星系天体物理 · 物理学 2018-12-18 W. F. Thi , S. Hocuk , I. Kamp , P. Woitke , Ch. Rab , S. Cazaux , P. Caselli
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