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相关论文: HCO, c-C3H and CF+ : three new molecules in diffus…

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To provide constraints on the chemical processes responsible for the observed columns of organic species, we used NOEMA to observe the sight line toward NRAO150 in the 2mm spectral window. We targeted the low excitation lines of o-H2CO…

星系天体物理 · 物理学 2024-05-29 Maryvonne Gerin , Harvey Liszt , Jerome Pety , Alexandre Faure

We modelled \HH\ and CO formation incorporating the fractionation and selective photodissociation affecting CO when \AV\ $\la2$mag. UV absorption measurements typically have N(\cotw)/N(\coth) $\approx 65$ that are reproduced with the…

星系天体物理 · 物理学 2017-02-01 Harvey S. Liszt

ALMA data toward QSO J1851+0035 ($l$=$33.498^{\circ}$, $b$=$+0.194^{\circ}$) were used to study absorption lines by Galactic molecular gas. We detected 17 species (CO, $^{13}$CO, C$^{18}$O, HCO$^+$, H$^{13}$CO$^+$, HCO, H$_2$CO, C$_2$H,…

星系天体物理 · 物理学 2024-04-16 Kanako Narita , Seiichi Sakamoto , Jin Koda , Yuki Yoshimura , Kotaro Kohno

Absorption lines from the molecules OH+, H2O+, and H3+ have been observed in a diffuse molecular cloud along a line of sight near W51 IRS2. We present the first chemical analysis that combines the information provided by all three of these…

星系天体物理 · 物理学 2015-06-11 Nick Indriolo , D. A. Neufeld , M. Gerin , T. R. Geballe , J. H. Black , K. M. Menten , J. R. Goicoechea

We acquired ALMA ground state absorption profiles of HCO+ and other molecules toward 33 extragalactic continuum sources seen toward the Galactic anticenter, deriving N(H2) = N(HCO+)/3x10^{-9}. We observed J=1-0 CO emission with the IRAM 30m…

星系天体物理 · 物理学 2023-07-19 Harvey Liszt , Maryvonne Gerin

We present new H I 21 cm absorption data and ultraviolet spectroscopy from HST/STIS of the QSO/galaxy pair 3C 232/NGC 3067. The QSO sightline lies near the minor axis and 1.8 arcmin (11 kpc) above the plane of NGC 3067, a nearby luminous…

天体物理学 · 物理学 2009-11-10 Brian A. Keeney , Emmanuel Momjian , John T. Stocke , Chris L. Carilli , Jason Tumlinson

We have conducted a spectral line survey in the 3 mm and 2 mm bands toward two positions in a spiral arm of M51 (NGC 5194) with the IRAM 30 m telescope. In this survey, we have identified 13 molecular species, including CN, CCH, N2H+, HNCO,…

星系天体物理 · 物理学 2015-06-19 Yoshimasa Watanabe , Nami Sakai , Kazuo Sorai , Satoshi Yamamoto

As a complement to the HyGAL Stratospheric Observatory for Infrared Astronomy Legacy Program, we report the results of a ground-based absorption line survey of simple molecules in diffuse and translucent Galactic clouds. Using the Institut…

Context. In the near- to mid-infrared wavelength domain, bright continuum sources in the central parsec of the Galactic center (GC) are subject to foreground absorption. These sources therefore represent ideal probes of the intervening…

星系天体物理 · 物理学 2019-06-12 Jihane Moultaka , Andreas Eckart , Kiran Tikare , Armelle Bajat

Infrared absorption lines of H3+, including the metastable R(3,3)l line, have been observed toward eight bright infrared sources associated with hot and massive stars located in and between the Galactic Center Cluster and the Quintuplet…

天体物理学 · 物理学 2009-11-13 Miwa Goto , T. Usuda , T. Nagata , T. R. Geballe , B. J. McCall , N. Indriolo , H. Suto , Th. Henning , C. P. Morong , Takeshi Oka

There is a robust polyatomic chemistry in diffuse, partially-molecular interstellar gas that is readily accessible in absorption at radio/mm/sub-mm wavelengths. Accurate column densities are derived owing to the weak internal excitation, so…

星系天体物理 · 物理学 2023-02-15 Harvey Liszt , Maryvonne Gerin

We present new groundbased 3 $\mu$m spectra of 14 young stellar objects with H_2O ice absorption bands. The broad absorption feature at 3.47 $\mu$m was detected toward all objects and its optical depth is correlated with the optical depth…

天体物理学 · 物理学 2009-10-31 T. Y. Brooke , K. Sellgren , T. R. Geballe

We present evidence of 6.7 GHz methanol (CH3OH)~and 4.8 GHz formaldehyde (H2CO) absorption towards the Galactic Center (GC) point-source `N3'. Both absorption features are unresolved and spatially aligned with N3. The 6.7 GHz CH3OH contains…

Infrared Dark Clouds are expected to harbor sources in different, very young evolutionary stages. To better characterize these differences, we observed a sample of 43 massive Infrared Dark Clouds, originally selected as candidate high-mass…

天体物理学 · 物理学 2019-08-19 H. Beuther , T. K. Sridharan

Until now the known sources in the Galactic center with sufficiently smooth spectra and of sufficient brightness to be suitable for high resolution infrared absorption spectroscopy of interstellar gas occupied a narrow range of longitudes,…

星系天体物理 · 物理学 2015-05-14 T. R. Geballe , T. Oka

In the Halo21 absorption modeling challenge we generated synthetic absorption spectra of the circumgalactic medium (CGM), and attempted to estimate the metallicity, temperature, and density (Z, T, and nH) of the underlying gas using…

We have used the Cosmic Origins Spectrograph (COS) to obtain far-UV spectra of three closely-spaced QSO sight lines that probe the circumgalactic medium (CGM) of an edge-on spiral galaxy, ESO 157-49, at impact parameters of 74 and 93 kpc…

Context: An unexpectedly complex polyatomic chemistry exists in diffuse clouds, allowing detection of species such as C2H, C3H2, H2CO and NH3 which have relative abundances that are strikingly similar to those inferred toward the dark cloud…

星系天体物理 · 物理学 2009-01-21 H. S. Liszt , J. Pety , R. Lucas