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Related papers: A New H I Survey of Active Galaxies

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Despite their importance for astrometry and navigation, the active galactic nuclei (AGNs) that comprise the International Celestial Reference Frame (ICRF) are relatively poorly understood, with key information such as their spectroscopic…

Astrophysics of Galaxies · Physics 2022-06-29 Remington O. Sexton , Nathan J. Secrest , Megan C. Johnson , Bryan N. Dorland

In this work, we aim to further populate the low-mass regime of black hole (BH) scaling relations to better understand the formation and growth mechanisms of central supermassive BHs. We target six galaxies that have been previously…

Astrophysics of Galaxies · Physics 2025-07-28 Megan R. Sturm , Amy E. Reines , Jenny Greene , Sheyda Salehirad

The Gaia mission has detected a large number of active galactic nuclei (AGN) and galaxies, but these objects must be identified among the 1000-fold more numerous stars. Extant astrometric AGN catalogs do not have the uniform sky coverage…

Astrophysics of Galaxies · Physics 2018-06-13 Jennie Paine , Jeremy Darling , Alexandra Truebenbach

The Arecibo Dual-Beam Survey is a "blind" 21 cm search for galaxies covering \~430 deg^2 of sky. We present the data from the detection survey as well as from the follow-up observations to confirm detections and improve positions and flux…

Astrophysics · Physics 2009-10-31 Jessica L. Rosenberg , Stephen E. Schneider

Active galactic nuclei (AGN) are supermassive black holes with luminous accretion disks found in some galaxies, and are thought to play an important role in galaxy evolution. However, traditional optical spectroscopy for identifying AGN…

Astrophysics of Galaxies · Physics 2022-12-16 Ziting Guo , John F. Wu , Chelsea E. Sharon

We report the discovery using Spitzers high resolution spectrograph of 7 Active Galactic Nuclei (AGN) in a sample of 32 late-type galaxies that show no definitive signatures of AGN in their optical spectra. Our observations suggest that the…

Astrophysics · Physics 2009-11-13 S. Satyapal , D. Vega , R. P. Dudik , N. P. Abel , T. Heckman

The neutral hydrogen properties of 1,822 galaxies are being studied with the Green Bank 100m and the Parkes 64m telescopes as part of the 'Cosmic Flows' program. Observed parameters include systemic velocities, profile line widths, and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Helene M. Courtois , R. Brent Tully , D. I. Makarov , S. Mitronova , B. Koribalski , I. D. Karachentsev , J. Richard Fisher

We investigate the kinematic properties of Galactic HII regions using radio recombination line (RRL) emission detected by the Australia Telescope Compact Array (ATCA) at 4-10 GHz and the Jansky Very Large Array (VLA) at 8-10 GHz. Our HII…

Astrophysics of Galaxies · Physics 2021-11-24 Dana S. Balser , Trey V. Wenger , L. D. Anderson , W. P. Armentrout , T. M. Bania , J. R. Dawson , John M. Dickey

We use a large N-body simulation to examine the detectability of HI in emission at redshift z ~ 1, and the constraints imposed by current observations on the neutral hydrogen mass function of galaxies at this epoch. We consider three…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Nishikanta Khandai , Shiv K. Sethi , Tiziana Di Matteo , Rupert A. C. Croft , Volker Springel , Anirban Jana , Jeffrey P. Gardner

Neutral hydrogen mapping of 70 dwarf irregular (Sm, Im and BCD) galaxies is reported, with position-velocity contour maps presented for those resolved by the Arecibo beam. The galaxies were selected either from the Virgo Cluster Catalog,…

Astrophysics · Physics 2009-10-28 G. L. Hoffman , E. E. Salpeter , B. Farhat , T. Roos , H. Williams , G. Helou

We present the third catalog release of the wide-area (31.3 deg$^2$) Stripe 82 X-ray survey. This catalog combines previously published X-ray source properties with multiwavelength counterparts and photometric redshifts, presents 343 new…

We present a first statistical sample of faint type-1 AGNs at $z>4$ identified by JWST/NIRSpec deep spectroscopy. Among the 185 galaxies at $z_\mathrm{spec}=3.8-8.9$ confirmed with NIRSpec, our systematic search for broad-line emission…

Astrophysics of Galaxies · Physics 2023-10-31 Yuichi Harikane , Yechi Zhang , Kimihiko Nakajima , Masami Ouchi , Yuki Isobe , Yoshiaki Ono , Shun Hatano , Yi Xu , Hiroya Umeda

The tight correlations between the mass of supermassive black holes ($M_{\rm BH}$) and their host-galaxy properties have been of great interest to the astrophysical community, but a clear understanding of their origin and fundamental…

We present 21 cm observations of a 10 $\times$ 2 degree region in the Virgo cluster, obtained as part of the Arecibo Galaxy Environment Survey. 289 sources are detected over the full redshift range (-2,000 $<$ $v$$_{hel}$ $<$ + 20,000 km/s)…

Astrophysics of Galaxies · Physics 2015-06-04 R. Taylor , J. I. Davies , R. Auld , R. F. Minchin

The joint catalogue of Active Galactic Nuclei selected from optical identifications of X-ray sources was created as a combination of two samples: Hamburg-ROSAT Catalogue (HRC) and Byurakan-Hamburg-ROSAT Catalogue (BHRC). Both are based on…

Astrophysics of Galaxies · Physics 2015-11-24 A. M. Mickaelian , G. M. Paronyan , G. S. Harutyunyan , H. V. Abrahamyan , M. V. Gyulzadyan

We report R~3000 VLT ISAAC K-band spectroscopy of the nuclei (i.e. central 100-300pc) of 9 galaxies hosting an active galactic nucleus. For 5 of these we also present spectra of the circumnuclear region out to 1kpc. We have measured a…

Astrophysics · Physics 2009-11-13 R. I. Davies , A. Sternberg , M. D. Lehnert , L. E. Tacconi-Garman

High sensitivity (rms noise $\sim 0.5$ mJy) 21-cm HI line observations were made of 33 galaxies in the Virgo cluster, using the refurbished Arecibo telescope, which resulted in the detection of 12 objects. These data, combined with the…

Astrophysics · Physics 2009-11-10 G. Gavazzi , A. Boselli , W. van Driel , K. O'Neil

We present the sixth list with results of the Hamburg/SAO Survey for Emission-Line Galaxies. The final list resulted from follow-up spectroscopy conducted with the 4.5m MMT telescope in 1996, and with 2.2m CAHA and 6m SAO telescopes in 2000…

We present measurements of the dust attenuation of H\alpha-selected emission-line galaxies at z=0.8 from the NewH\alpha\ narrowband survey. The analysis is based on deep follow-up spectroscopy with Magellan/IMACS, which captures the strong…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Ivelina Momcheva , Janice C. Lee , Chun Ly , Samir Salim , Daniel A. Dale , Masami Ouchi , Rose Finn , Yoshiaki Ono

We study the relation of active galactic nuclei (AGNs) to star formation in their host galaxies. Our sample includes 205 Type-1 and 85 Type-2 AGNs, 162 detected with Herschel, from fields surrounding 30 galaxy clusters in the Local Cluster…

Astrophysics of Galaxies · Physics 2015-08-19 Lei Xu , G. H. Rieke , E. Egami , C. P. Haines , M. J. Pereira , G. P. Smith