English
Related papers

Related papers: Helium line detections from ELDWIM at 1.4 GHz

200 papers

We present a systematic study of deuterated molecular hydrogen (HD) at high redshift, detected in absorption in the spectra of quasars. We present four new identifications of HD lines associated with known $\rm H_2$-bearing Damped…

Astrophysics of Galaxies · Physics 2021-06-30 D. N. Kosenko , S. A. Balashev , P. Noterdaeme , J. -K. Krogager , R. Srianand , C. Ledoux

We report statistically significant detection of H I 21-cm emission from intermediate-redshift ($z\approx0.2$-0.6) galaxies. By leveraging multi-sightline galaxy survey data from the Cosmic Ultraviolet Baryon Survey (CUBS) and deep radio…

Most of cosmic baryons predicted by the big-bang nucleosynthesis has evaded the direct detection. Recent numerical simulations indicate that approximately 30 to 50 percent of the total baryons in the present universe is supposed to take a…

The census of Galactic HII regions is vastly incomplete in the Southern sky. We use the Australia Telescope Compact Array (ATCA) to observe 4-10 GHz radio continuum and hydrogen radio recombination line (RRL) emission from candidate HII…

We report the detection of stimulated hydrogen radio recombination line (RRL) emission from ionized gas in a $z=0.89$ galaxy using 580--1670 MHz observations from the MeerKAT Absorption Line Survey (MALS). The RRL emission originates in a…

We present high resolution [NII] 205 micrometer ^3P_1-^3P_0 spectra obtained with Herschel-HIFI towards a small sample of far-infrared bright star forming regions in the Galactic plane: W31C (G10.6-0.4), W49N (G43.2-0.1), W51 (G49.5-0.4),…

Observations of 21-cm radio emission by neutral hydrogen at redshifts z ~ 0.5 to ~ 2.5 are expected to provide a sensitive probe of cosmic dark energy. This is particularly true around the onset of acceleration at z ~ 1, where traditional…

Cosmology and Nongalactic Astrophysics · Physics 2010-07-22 Tzu-Ching Chang , Ue-Li Pen , Kevin Bandura , Jeffrey B. Peterson

Observations of millimeter wavelength radio recombination lines (mm-RRLs) are used to search for HII regions in an unbiased way that is complementary to many of the more traditional methods previously used. We carried out targeted mm-RRL…

Astrophysics of Galaxies · Physics 2017-06-07 W. -J. Kim , F. Wyrowski , J. S. Urquhart , K. M. Menten , T. Csengeri

We have used the Westerbork array to carry out an unbiased wide-field survey for HI emission features, achieving an RMS sensitivity of about 18 mJy/Beam at a velocity resolution of 17 km/s over 1800 deg^2 and between -1000 < V_Hel<+6500…

Astrophysics · Physics 2016-08-30 Robert Braun , David Thilker , Rene Walterbos

We investigate the possibility of detecting HI emission from gravitationally lensed HI clouds (akin to damped Lyman-$\alpha$ clouds) at high redshift by carrying out deep radio observations in the fields of known cluster lenses. Such…

Astrophysics · Physics 2017-03-22 Tarun Deep Saini , Somnath Bharadwaj , Shiv Kumar Sethi

In this contribution, we present some preliminary observational results from the completed ultra-deep survey of 21cm emission from neutral hydrogen at redshifts z=0.164-0.224 with the Westerbork Synthesis Radio Telescope. In two separate…

We present the first data release of high-resolution ($\leq0.2$ arcsec) 1.5-GHz radio images of 103 nearby galaxies from the Palomar sample, observed with the eMERLIN array, as part of the LeMMINGs survey. This sample includes galaxies…

Neutral Hydrogen (HI) provides a very important fuel for star formation, but is difficult to detect at high redshift due to weak emission, limited sensitivity of modern instruments, and terrestrial radio frequency interference (RFI) at low…

Astrophysics of Galaxies · Physics 2016-07-20 Lucas R. Hunt , D. J. Pisano , Stanislav S. Edel

The Green Bank Telescope HII Region Discovery Survey has doubled the number of known HII regions in the Galactic zone 343deg.\leql\leq67deg. with |b|\leq1deg. We detected 603 discrete hydrogen radio recombination line (RRL) components at…

Astrophysics of Galaxies · Physics 2015-05-27 L. D. Anderson , T. M. Bania , Dana S. Balser , Robert T. Rood

(abridged) We present 8.2m VLT spectroscopic observations of 28 HII regions in 16 emission-line galaxies and 3.6m ESO telescope spectroscopic observations of 38 HII regions in 28 emission-line galaxies. These emission-line galaxies were…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-30 N. G. Guseva , P. Papaderos , H. T. Meyer , Y. I. Izotov , K. J. Fricke

We study the radio properties at 1.4 GHz of Seyfert galaxies with strong forbidden high-ionization lines (FHILs), selected from the Sloan Digital Sky Survey - a large-sized sample containing nearly equal proportion of diverse range of…

Astrophysics of Galaxies · Physics 2016-01-05 Dharam V. Lal

We have observed the DEEP2 galaxies using the Giant Meterwave Radio Telescope in the frequency band of 610 MHz. There are $\simeq 400$ galaxies in the redshift range $1.24 < z < 1.36$ and within the field of view $\simeq 44'$, of the GMRT…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-20 Shiv K. Sethi , K. S. Dwarakanath , Chandrashekar Murugesan

A large fraction of baryons predicted from the standard cosmology has been missing observationally. Although previous numerical simulations have indicated that most of the missing baryons reside in large-scale filaments in the form of Warm…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-20 Toshihiro Horii , Shinsuke Asaba , Kenji Hasegawa , Hiroyuki Tashiro

We present an HI 21cm absorption study of a sample of 26 radio-loud active galactic nuclei (AGN) at $0.25 < z < 0.4$ carried out with the Karl G. Jansky Very Large Array. Our aim was to study the rate of incidence of HI in various classes…

Astrophysics of Galaxies · Physics 2021-10-20 Suma Murthy , Raffaella Morganti , Tom Oosterloo , Filippo M. Maccagni

Using a spectral stacking technique, we measure the neutral hydrogen (HI) properties of a sample of galaxies at $z < 0.11$ across 35 pointings of the Westerbork Synthesis Radio Telescope (WSRT). The radio data contains 1,895 galaxies with…