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Related papers: Helium line detections from ELDWIM at 1.4 GHz

200 papers

We present new L-band ($1\mbox{--}2$ GHz) observations of the nearby spiral galaxy M33 with 80 pc resolution obtained with the Karl G. Jansky Very Large Array. The HI observations, combined with HI measurements from the Green Bank…

Quasars that allow the study of IGM He II are very rare, since they must be at high redshift along sightlines free of substantial hydrogen absorption, but recent work has dramatically expanded the number of such quasars known. We analyze…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 David Syphers , Scott F. Anderson , Wei Zheng , Avery Meiksin , Daryl Haggard , Donald P. Schneider , Donald G. York

The v =1-0 R(5) line of HD at 2.46um has been detected at the position of brightest line emission of shocked H2 in the Orion Molecular Cloud. The flux in this HD line, when compared to that of the previously detected HD 0--0 R(5) line at…

Astrophysics · Physics 2009-11-07 T. R. Geballe , S. K. Ramsay Howat , R. Timmermann , F. Bertoldi , C. M. Mountain

We present a survey for low-ionization metal absorption line systems towards 17 QSOs at redshifts z_em=5.8-6.4. Nine of our objects were observed at high resolution with either Keck/HIRES or Magellan/MIKE, and the remainder at moderate…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 George D. Becker , Wallace L. W. Sargent , Michael Rauch , Alexander P. Calverley

I review the potential for observing cosmic reionization using the HI 21cm line of neutral hydrogren. Studies include observations of the evolution of large scale structure of the IGM (density, excitation temperature, and neutral fraction),…

Astrophysics · Physics 2009-11-13 C. L. Carilli

We analyze line-of-sight atomic hydrogen (HI) line profiles of 31 nearby, low-mass galaxies selected from the Very Large Array - ACS Nearby Galaxy Survey Treasury (VLA-ANGST) and The HI Nearby Galaxy Survey (THINGS) to trace regions…

We present the first detection of the l-C3H+ hydrocarbon in the interstellar medium. The Horsehead WHISPER project, a millimeter unbiased line survey at two positions, namely the photo-dissociation region (PDR) and the nearby shielded core,…

Nearby interstellar clouds with high (|v| >/= 10 km/s) random velocities although easily detected in NaI and CaII lines have hitherto not been detected (in emission or absorption) in the HI 21cm line. We describe here deep Giant Metrewave…

Astrophysics · Physics 2009-11-06 Rekhesh Mohan , K. S. Dwarakanath , G. Srinivasan , Jayaram N. Chengalur

Orion KL has served as a benchmark for spectral line searches throughout the (sub)millimeter regime. The main goal is to systematically study spectral characteristics of Orion KL in the 1.3 cm band. We carried out a spectral line survey…

Astrophysics of Galaxies · Physics 2015-09-03 Y. Gong , C. Henkel , S. Thorwirth , S. Spezzano , K. M. Menten , C. M. Walmsley , F. Wyrowski , R. Q. Mao , B. Klein

We present a study of hydrogen, helium, and carbon millimeter-wave radio-recombination lines (RRLs) toward ten representative positions throughout the Orion Nebula complex, using the Yebes 40m telescope in the Q band (31.3 GHz to 50.6 GHz)…

Astrophysics of Galaxies · Physics 2024-07-31 C. H. M. Pabst , J. R. Goicoechea , S. Cuadrado , P. Salas , A. G. G. M. Tielens , N. Marcelino

Neutral atomic hydrogen and molecular gas in the host galaxies of radio active galactic nuclei (AGN) can be traced using H I 21-cm and OH-1667 MHz absorption lines to understand the fueling and feedback processes. We present the results of…

Astrophysics of Galaxies · Physics 2024-07-01 Yogesh Chandola , D. J. Saikia , Yin-Zhe Ma , Zheng Zheng , Chao-Wei Tsai , Di Li , Denis Tramonte , Hengxing Pan

We determine the radial abundance gradient of helium in the disc of the Galaxy from published spectra of 19 $\text{H}\thinspace \text{II}$ regions and ring nebulae surrounding massive O stars. We revise the Galactocentric distances of the…

Solar and Stellar Astrophysics · Physics 2020-06-16 J. E. Méndez-Delgado , C. Esteban , J. García-Rojas , K. Z. Arellano-Córdova , M. Valerdi

A Square Kilometer Array radio telescope will detect tens of thousands of galaxies per square degree in the 21cm emission line of neutral hydrogen. The telescope will be sensitive to ordinary galaxy populations at redshifts z>3 when the…

Astrophysics · Physics 2016-08-30 F. H. Briggs

The mutually complementary Euclid and Roman galaxy redshift surveys will use Halpha- and [OIII]-selected emission line galaxies as tracers of the large scale structure at $0.9 \lesssim z \lesssim 1.9$ (Halpha) and $1.5 \lesssim z \lesssim…

Ly$\alpha$ emission from galaxies can be utilized to characterize the ionization state in the intergalactic medium (IGM). We report our search for Ly$\alpha$ emission at $z>7$ using a comprehensive Keck/MOSFIRE near-infrared spectroscopic…

Integral field spectroscopy of the central parsec of the Galactic Center was obtained at 2.06 microns using BEAR, an imaging Fourier Transform Spectrometer, at a spectral resolution of 74 km/s. Sixteen stars were confirmed as helium stars…

Astrophysics · Physics 2016-08-30 T. Paumard , J. P. Maillard , M. Morris , F. Rigaut

The extended environment of galaxies contains a wealth of information about the formation and life cycle of galaxies which are regulated by accretion and feedback processes. Observations of neutral hydrogen are routinely used to image the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Attila Popping , Robert Braun

We present the second data release of high-resolution ($\leq0.2$ arcsec) 1.5-GHz radio images of 177 nearby galaxies from the Palomar sample, observed with the e-MERLIN array, as part of the LeMMINGs (Legacy e-MERLIN Multi-band Imaging of…

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