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相关论文: A Very Sensitive 21cm Survey for Galactic High-Vel…

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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,…

星系天体物理 · 物理学 2023-12-19 Francoise Combes , Neeraj Gupta

In order to investigate the contribution of diffuse components to their total HI emission, we have obtained high precision HI line flux densities with the 100m Green Bank Telescope for a sample of 100 isolated spiral and irregular galaxies…

天体物理学 · 物理学 2008-11-26 David E. Hogg , Morton S. Roberts , Martha P. Haynes , Ronald J. Maddalena

Atomic Hydrogen-21 cm transition (HI) is an excellent tracer to study and understand the properties of the atomic gas in the Galaxy. Using the Westerbork Synthesis Radio Telescope (WSRT), we observed 12 quasar sightlines to detect galactic…

星系天体物理 · 物理学 2024-03-19 Narendra Nath Patra , Nirupam Roy

We report observations of 15 high redshift (z = 1-5) galaxies at 350 microns using the Caltech Submillimeter Observatory and SHARC-II array detector. Emission was detected from eight galaxies, for which far-infrared luminosities, star…

宇宙学与河外天体物理 · 物理学 2014-11-20 Jingwen Wu , Paul Vanden Bout , Neal Evans , Michael Dunham

We have detected HI 21cm line absorption by the Warm Neutral Medium (WNM) using the Westerbork Synthesis Radio Telescope. The absorption was detected toward Cygnus A at LSR velocities of -40 and -70 km s^{-1}. These two velocity ranges were…

天体物理学 · 物理学 2009-10-30 C. L. Carilli , K. S. Dwarakanath , W. M. Goss

A set of diffuse interstellar clouds in the inner Galaxy within a few hundred pc of the Galactic plane has been observed at an angular resolution of ~1 arcmin combining data from the NRAO Green Bank Telescope and the Very Large Array. At…

星系天体物理 · 物理学 2015-06-15 Yurii Pidopryhora , Felix J. Lockman , John M. Dickey , Michael P. Rupen

We have carried out deep, high velocity resolution, interferometric Galactic HI 21 cm absorption spectroscopy towards 32 compact extra-galactic radio sources with the Giant Metrewave Radio Telescope (GMRT) and the Westerbork Synthesis Radio…

星系天体物理 · 物理学 2014-07-30 Nirupam Roy , Nissim Kanekar , Robert Braun , Jayaram N. Chengalur

Neutral hydrogen (HI) is the primary component of the cool interstellar medium (ISM) and is the reservoir of fuel for star formation. Owing to the sensitivity of existing radio telescopes, our understanding of the evolution of the ISM in…

Neutral hydrogen mapping of several small, very low column density High Velocity Clouds (HVC), using the Arecibo telescope, is reported. Some were found serendipitously superimposed at distinct velocities on largerHVCs; others were found to…

天体物理学 · 物理学 2009-11-10 G. Lyle Hoffman , E. E. Salpeter , Ajay Hirani

A mosaic of six HI line observations with the Australia Telescope Compact Array is used to search for intergalactic gas in the NGC 1808 group of galaxies. Within the field of view of about 1.4 deg x 1.2 deg, no emission from intergalactic…

天体物理学 · 物理学 2009-11-06 Michael Dahlem , Matthias Ehle , Stuart D. Ryder

Using a sample of nearly half million galaxies, intersected by over 7 million lines of sight from the Sloan Digital Sky Survey Data Release 12, we trace H$\alpha$ + [N{\small II}] emission from a galactocentric projected radius, $r_p$, of 5…

星系天体物理 · 物理学 2016-12-28 Huanian Zhang , Dennis Zaritsky , Guangtun Zhu , Brice Ménard , David W. Hogg

We present new, accurate positions, spectral classifications, radial and rotational velocities, H-alpha fluxes, equivalent widths and B,V,I,R magnitudes for 579 hot emission-line stars (classes B0 - F9) in the Large Magellanic Cloud which…

太阳与恒星天体物理 · 物理学 2015-06-05 Warren A. Reid , Quentin A. Parker

We present the results of a new sensitive survey of neutral hydrogen above and below the Galactic Center with the Green Bank Telescope. The observations extend up to Galactic latitude | b | < 10 deg with an effective angular resolution of…

The Magellanic Stream, a tidal tail of diffuse gas falling onto the Milky Way, formed by interactions between the Small and Large Magellanic Clouds, is primarily composed of neutral atomic hydrogen (HI). The deficiency of dust and the…

Far-infrared line and continuum fluxes are presented for a sample of 227 galaxies observed with the Long Wavelength Spectrometer on the Infrared Space Observatory. The galaxy sample includes normal star-forming systems, starbursts, and…

天体物理学 · 物理学 2009-11-13 James R. Brauher , Daniel A. Dale , George Helou

The WISE Catalog of Galactic HII Regions contains $\sim2000$ HII region candidates lacking ionized gas spectroscopic observations. All candidates have the characteristic HII region mid-infrared morphology of WISE $12\,\,\mu\,m$ emission…

We have developed an automated cross-correlation technique to detect 21cm emission in sample spectra obtained from the HI Parkes All Sky Survey. The initial sample selection was the nearest spectra to 2435 low surface brightness galaxies in…

The Ly$\alpha$ emission line is one of the main observables of galaxies at high redshift, but its output depends strongly on the neutral gas distribution and kinematics around the star-forming regions where UV photons are produced. We…

Optical emission lines have now been detected from about 20 high velocity clouds. These emission lines -- primarily H-alpha, secondarily [N II] and [S II] -- are very faint and diffuse, spread over the surfaces of the clouds. We compile…

天体物理学 · 物理学 2007-05-23 Benjamin J. Weiner , Stuart N. Vogel , T. B. Williams

Our view of the high velocity cloud (HVC) system is changing dramatically with new observations from the Far Ultraviolet Spectroscopic Explorer mission and the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope. In…

天体物理学 · 物理学 2007-05-23 Kenneth R. Sembach