scholarly journals High-Redshift Molecular Clouds and Absorption-Line Spectra of Quasars

1983 ◽  
Vol 104 ◽  
pp. 365-366
Author(s):  
D. A. Varshalovich ◽  
S. A. Levshakov
Keyword(s):  
Absorption Line ◽  
Molecular Clouds ◽  
High Redshift ◽  
Optical Spectra ◽  
Molecular Lines

The optical spectra of distant quasars (OQ 172, PHL 957, PKS 0237–233 and 11 others) were reanalysed with the purpose of searching molecular lines /2, 4/.

scholarly journals Extragalactic science with ALMA

2011 ◽  
Vol 7 (S284) ◽  
pp. 494-495
Author(s):  
George J. Bendo ◽  
Keyword(s):  
Molecular Clouds ◽  
High Redshift ◽  
Atacama Desert ◽  
Line Emission ◽  
Continuum Emission ◽  
Synchrotron Emission ◽  
Molecular Line ◽  
Molecular Lines ◽  
Nearby Galaxies ◽  
Detailed Imaging

AbstractThe Atacama Large Millimeter/submillimeter Array (ALMA) is a telescope comprising 66 antennas that is located in the Atacama Desert in Chile, one of the driest locations on Earth. When the telescope is fully operational, it will perform observations over ten receiver bands at wavelengths from 9.5-0.32 mm (31-950 GHz) with unprecedented sensitivities to continuum emission from cold (<20 K) dust, Bremsstrahlung, and synchrotron emission as well as submillimetre and millimetre molecular lines. With baselines out to 16km and dynamic reconfiguration, ALMA will achieve spatial resolutions ranging from 3″ to 0.010″, allowing for detailed imaging of continuum or molecular line emission from 0.1-1 kpc scale gas and dust discs in high-redshift sources or 10-100 pc scale molecular clouds and substructures within nearby galaxies. Science observations started on 30 September 2011 with 16 antennas and four receiver bands on baselines up to 400 m. The telescope's capabilities will steadily improve until full operations begin in 2013.

scholarly journals The global star formation law: from dense cores to extreme starbursts

2006 ◽  
Vol 2 (S237) ◽  
pp. 331-335
Author(s):  
Yu Gao
Keyword(s):  
Star Formation ◽  
Linear Correlation ◽  
Molecular Clouds ◽  
High Redshift ◽  
Gas Content ◽  
Molecular Gas ◽  
Giant Molecular Clouds ◽  
Active Star ◽  
Dense Cores ◽  
The Galaxy

AbstractActive star formation (SF) is tightly related to the dense molecular gas in the giant molecular clouds' dense cores. Our HCN (measure of the dense molecular gas) survey in 65 galaxies (including 10 ultraluminous galaxies) reveals a tight linear correlation between HCN and IR (SF rate) luminosities, whereas the correlation between IR and CO (measure of the total molecular gas) luminosities is nonlinear. This suggests that the global SF rate depends more intimately upon the amount of dense molecular gas than the total molecular gas content. This linear relationship extends to both the dense cores in the Galaxy and the hyperluminous extreme starbursts at high-redshift. Therefore, the global SF law in dense gas appears to be linear all the way from dense cores to extreme starbursts, spanning over nine orders of magnitude in IR luminosity.

scholarly journals HS 1700+6416: the first high-redshift unlensed narrow absorption line-QSO showing variable high-velocity outflows

2012 ◽  
Vol 544 ◽  
pp. A2 ◽  
Author(s):  
G. Lanzuisi ◽  
M. Giustini ◽  
M. Cappi ◽  
M. Dadina ◽  
G. Malaguti ◽  
...  
Keyword(s):  
Absorption Line ◽  
High Velocity ◽  
High Redshift

scholarly journals Limits on the Variation of Physical Constants Derived from Molecular Absorption Lines

1999 ◽  
Vol 183 ◽  
pp. 167-167 ◽  
Author(s):  
T. Wiklind ◽  
F. Combes
Keyword(s):  
Absorption Line ◽  
High Redshift ◽  
Absorption Lines ◽  
Frequency Resolution ◽  
Radio Lines ◽  
Molecular Absorption ◽  
Diagnostic Application ◽  
Physical Constants ◽  
Resonance Transitions ◽  
Electronic Resonance

A potential diagnostic application of molecular rotational absorption lines at high redshift is to test the invariance of physical constants. This can be done by comparing the observed redshifted frequency of a molecular absorption line with redshifted lines from other types of transitions such as the 21cm hyperfine transition or electronic resonance transitions. In order to set stringent limits, it is necessary to achieve the greatest possible frequency resolution. This makes radio lines well suited for this purpose.

scholarly journals An extensive study of interstellar matter in the IC 1396 region using several molecular lines and transitions of CO and far-infrared maps from IRAS

1991 ◽  
Vol 147 ◽  
pp. 513-514
Author(s):  
H. Weikard ◽  
K. Sugitani ◽  
G. Duvert ◽  
M. Miller
Keyword(s):  
Molecular Clouds ◽  
Far Infrared ◽  
Extensive Study ◽  
Interstellar Matter ◽  
Molecular Lines ◽  
H Ii Region

IC 1396 is an H II region in Cepheus excited by the massive 06.5 star HD 206267. The distance is about 750 pc. The region exhibits a number of bright-rimmed molecular clouds in which outflows have been detected (Sugitani et al. 1989, Duvert et al. 1990).

A study of the absorption-line spectra of six high-redshift quasi-stellar objects

1978 ◽  
Vol 224 ◽  
pp. 344 ◽  
Author(s):  
D. H. Roberts ◽  
G. R. Burbidge ◽  
A. H. Crowne ◽  
V. T. Junkkarinen ◽  
E. M. Burbidge ◽  
...  
Keyword(s):  
Absorption Line ◽  
High Redshift ◽  
Stellar Objects ◽  
Quasi Stellar Objects

scholarly journals Radio Line and Continuum Observations of Quasar-Galaxy Pairs and the Origin of Low Redshift Quasar Absorption Line Systems

1990 ◽  
Vol 124 ◽  
pp. 473-477
Author(s):  
C.L. Carilli ◽  
J.H. van Gorkom ◽  
E.M. Hauxthausen ◽  
J.T. Stocke ◽  
J. Salzer
Keyword(s):  
Absorption Line ◽  
Alternative Hypothesis ◽  
High Redshift ◽  
Gravitational Interaction ◽  
Optical Disk ◽  
Line Of Sight ◽  
Radio Line ◽  
Redshift Galaxy ◽  
Interacting Systems ◽  
Companion Galaxy

There are a number of known quasars for which our line of sight to the high redshift quasar passes within a few Holmberg radii of a low redshift galaxy. In a few of these cases, spectra of the quasar reveal absorption by gas associated with the low redshift galaxy. A number of these pairs imply absorption by gas which lies well outside the optical disk of the associated galaxy, leading to models of galaxies with ‘halos’ or ‘disks’ of gas extending to large radii. We present observations of 4 such pairs. In three of the four cases, we find that the associated galaxy is highly disturbed, typically due to a gravitational interaction with a companion galaxy, while in the fourth case the absorption can be explained by clouds in the optical disk of the associated galaxy. We are led to an alternative hypothesis concerning the origin of the low redshift absorption line systems: the absorption is by gas clouds which have been gravitationally stripped from the associated galaxy. These galaxies are rapidly evolving, and should not be used as examples of absorption by clouds in halos of field spirals. We conclude by considering the role extended gas in interacting systems plays in the origin of higher redshift quasar absorption line systems.

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