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200 papers

We have carried out a blind search in the general direction of the Galactic Anticenter for absorption of the Cosmic Microwave Background (CMB) radiation near 4.83 GHz by molecular clouds containing gaseous ortho-formaldehyde (H_2CO). The…

Astrophysics · Physics 2008-11-26 Monica Ivette Rodriguez , Ronald J. Allen , Laurent Loinard , Tommy Wiklind

Absorption lines at high redshift in front of quasars are rare in the mm domain. Only five associated and five intervening systems have been reported in the literature. These bring very useful information complementary to emission lines,…

Astrophysics of Galaxies · Physics 2023-12-19 Francoise Combes , Neeraj Gupta

We derive oxygen abundances for a sample of 40 luminous (M_{B} < -19), star-forming, mostly disk, field galaxies with redshifts in the range 0.2 < z < 0.8$, with a median of <z> = 0.45. Oxygen abundances, relative to hydrogen, of the…

Astrophysics · Physics 2009-11-11 M. Mouhcine , S. P. Bamford , A. Aragon-Salamanca , O. Nakamura

We have obtained a moderate resolution spectrum of the quasar PKS 0528-250 with the Red Channel Spectrograph on the Multiple Mirror Telescope (MMT) in order to study a damped Lyman alpha absorption line system at z = 2.8115. We obtain a new…

Astrophysics · Physics 2016-08-30 Jian Ge , Jill Bechtold , Constance Walker , John , H. Black

The Atacama Pathfinder Experiment (APEX) 12m telescope was used to observe the N=1-0, J=0-1 ground state transitions of OH+ at 909.1588 GHz with the CHAMP+ heterodyne array receiver. Two blended hyperfine structure transitions were detected…

Astrophysics of Galaxies · Physics 2015-05-18 F. Wyrowski , K. M. Menten , R. Guesten , A. Belloche

We present the results of a survey for HI 21-cm and OH 18-cm absorption in seven strong CO emitters at z > 3. Despite reaching limits comparable to those required to detect 21-cm absorption at lower redshifts, we do not detect either…

Astrophysics of Galaxies · Physics 2016-03-16 S. J. Curran , J. R. Allison , M. T. Whiting , E. M. Sadler , F. Combes , M. B. Pracy , C. Bignell , R. Athreya

We report the results of a search for molecular oxygen (O2) toward the Orion Bar, a prominent photodissociation region at the southern edge of the HII region created by the luminous Trapezium stars. We observed the spectral region around…

ORFEUS far UV echelle spectra have been used to investigate HI, H_2 and CO absorption lines along the line of sight towards LH 10:3120 in the LMC, extending the study presented by de Boer et al. (1998). While H_2 absorption is clearly…

Astrophysics · Physics 2007-05-23 P. Richter , K. S. de Boer , D. J. Bomans , Y. -N. Chin , A. Heithausen , J. Koornneef

We create stacked composite absorption spectra from Hubble Space Telescope Faint Object Spectrograph data from four quasi-stellar objects to search for absorption lines in the extreme ultraviolet wavelength region associated with LyA forest…

Astrophysics · Physics 2009-11-07 R. C. Telfer , G. A. Kriss , W. Zheng , A. F. Davidsen , D. Tytler

We report observations of the dust cloud L1204 with the Onsala 25-m telescope in the 6 cm (1$_{11}-1_{10}$) transition of \htco. The observed region includes the S140 H${\alpha}$ arc. This spectral line is seen here in absorption against…

Chandra high-resolution spectra toward eight low-mass Galactic binaries have been analyzed with a photoionization model that is capable of determining the physical state of the interstellar medium. Particular attention is given to the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 E. Gatuzz , J. García , C. Mendoza , T. R. Kallman , M. A. Bautista , T. W. Gorczyca

Models of pure gas-phase chemistry in well-shielded regions of molecular clouds predict relatively high levels of molecular oxygen, O2, and water, H2O. Contrary to expectation, the space missions SWAS and Odin found only very small amounts…

We report on one of the highest sensitivity surveys for molecular lines in the frequency range 6.0 to 7.4 GHz conducted to date. The observations were done with the 305m Arecibo Telescope toward a sample of twelve intermediate/high-mass…

Astrophysics of Galaxies · Physics 2020-07-08 W. S. Tan , E. D. Araya , L. E. Lee , P. Hofner , S. Kurtz , H. Linz , L. Olmi

The giant molecular cloud complex, Sgr B2, was observed with the ISO Long Wavelength Spectrometer over the range 47-197 microns. The ground state rotational transitions of OH lie in the survey range and we have analysed results from the…

Astrophysics · Physics 2007-05-23 E. T. Polehampton , J. -P. Baluteau , B. M. Swinyard

We describe a search for molecular absorption at millimetre wavelengths associated with dusty molecular tori in active galactic nuclei (AGN). The sample observed consists of 11 flat-spectrum radio sources known to have red optical to…

Astrophysics · Physics 2016-08-30 M. Drinkwater , F. Combes , T. Wiklind

Infrared OH lines at 1.55 - 1.56 um in the H-band were obtained with the Phoenix high-resolution spectrograph at the 2.1m telescope of the Kitt Peak National Observatory for a sample of 14 metal-poor stars. Detailed analyses of the sample…

Astrophysics · Physics 2011-02-11 Jorge Melendez , Beatriz Barbuy , Francois Spite

We have detected a broad interstellar absorption band centred close to 7700 \r{A} and with a FWHM of 176.6$\pm$3.9 \r{A}. This is the first such absorption band detected in the optical range and is significantly wider than the numerous…

Astrophysics of Galaxies · Physics 2021-01-13 J. Maíz Apellániz , R. H. Barbá , J. A. Caballero , R. C. Bohlin , C. Fariña

Using the Karl G. Jansky Very Large Array (VLA), we have detected absorption lines due to carbon-monoxide, CO(J=0-1), and the cyano radical, CN(N=0-1), associated with radio galaxy B2 0902+34 at redshift z=3.4. The detection of…

As part of the search for the "dark molecular gas (DMG)," we report on the results of HCO$^+$ J = 1-0 absorption observations toward nine bright extragalactic millimeter wave continuum sources. The extragalactic sources are at high Galactic…

Astrophysics of Galaxies · Physics 2018-07-04 Geumsook Park , Bon-Chul Koo , Kee-Tae Kim , Do-Young Byun , Carl E. Heiles