The existence of CA II absorption lines in the spectrum of the quasar 3C 232 due to the Galaxy NGC 3067

1978 ◽  
Vol 220 ◽  
pp. 42 ◽  
Author(s):  
A. Boksenberg ◽  
W. L. W. Sargent
Keyword(s):  
Absorption Lines ◽  
The Galaxy

Interstellar absorption lines in the galaxy NGC 1705

1990 ◽  
Vol 351 ◽  
pp. 412 ◽  
Author(s):  
D. G. York ◽  
A. Caulet ◽  
P. Rybski ◽  
J. Gallagher ◽  
J. C. Blades ◽  
...  
Keyword(s):  
Absorption Lines ◽  
Interstellar Absorption ◽  
The Galaxy

scholarly journals Hidden or missing outflows in highly obscured galaxy nuclei?

2019 ◽  
Vol 623 ◽  
pp. A29 ◽  
Author(s):  
N. Falstad ◽  
F. Hallqvist ◽  
S. Aalto ◽  
S. König ◽  
S. Muller ◽  
...  
Keyword(s):  
Line Emission ◽  
Far Infrared ◽  
Spectral Lines ◽  
Absorption Lines ◽  
Wide Angle ◽  
Vibrationally Excited ◽  
Molecular Outflows ◽  
Luminous Infrared Galaxies ◽  
The Galaxy ◽  
Central Regions

Context. Understanding the nuclear growth and feedback processes in galaxies requires investigating their often obscured central regions. One way to do this is to use (sub)millimeter line emission from vibrationally excited HCN (HCN-vib), which is thought to trace warm and highly enshrouded galaxy nuclei. It has been suggested that the most intense HCN-vib emission from a galaxy is connected to a phase of nuclear growth that occurs before the nuclear feedback processes have been fully developed. Aims. We aim to investigate if there is a connection between the presence of strong HCN-vib emission and the development of feedback in (ultra)luminous infrared galaxies ((U)LIRGs). Methods. We collected literature and archival data to compare the luminosities of rotational lines of HCN-vib, normalized to the total infrared luminosity, to the median velocities of 119 μm OH absorption lines, potentially indicating outflows, in a total of 17 (U)LIRGs. Results. The most HCN-vib luminous systems all lack signatures of significant molecular outflows in the far-infrared OH absorption lines. However, at least some of the systems with bright HCN-vib emission have fast and collimated outflows that can be seen in spectral lines at longer wavelengths, including in millimeter emission lines of CO and HCN (in its vibrational ground state) and in radio absorption lines of OH. Conclusions. We conclude that the galaxy nuclei with the highest LHCN − vib/LIR do not drive wide-angle outflows that are detectable using the median velocities of far-infrared OH absorption lines. This is possibly because of an orientation effect in which sources oriented in such a way that their outflows are not along our line of sight also radiate a smaller proportion of their infrared luminosity in our direction. It could also be that massive wide-angle outflows destroy the deeply embedded regions responsible for bright HCN-vib emission, so that the two phenomena cannot coexist. This would strengthen the idea that vibrationally excited HCN traces a heavily obscured stage of evolution before nuclear feedback mechanisms are fully developed.

Spectroscopy of the near-infrared afterglow of GRB 050904 at z = 6.3

2006 ◽  
Vol 2 (14) ◽  
pp. 264-264
Author(s):  
Nobuyuki Kawai
Keyword(s):  
Early Universe ◽  
Precise Measurement ◽  
Near Infrared ◽  
Absorption Lines ◽  
Heavy Elements ◽  
Star Forming ◽  
Long Wavelength ◽  
Faint Object ◽  
The Galaxy ◽  
Sharp Cutoff

AbstractWe present the optical/NIR spectrum of the afterglow of GRB 050904 obtained with the Faint Object Camera And Spectrograph on the Subaru 8.2m telescope taken 3.4 days after the burst. It is, as of June 2006, the only GRB with a known redshift larger than 6. The spectrum shows a clear continuum at the long wavelength end of the spectrum with a sharp cutoff at around 900nm due to Lyα absorption at a redshift of 6.3 with a damping wing. Little flux is present in the waveband shortward of the Lyα break. A system of absorption lines of heavy elements at redshift z = 6.295±0.002 were also detected, yielding a precise measurement of the largest known redshift of a GRB. Analysis of the silicon and sulphur absorption lines suggests a dense environment around the GRB with the metallicity larger than 0.1 solar, providing unique information on the galaxy and star forming region at z>6. This observation has shown that GRB is a powerful probe of the early universe.

scholarly journals 53. On the nature of the emission from the galaxy NGC 4486

1958 ◽  
Vol 6 ◽  
pp. 517-519
Author(s):  
I. S. Shklovsky
Keyword(s):  
Continuous Spectrum ◽  
Radio Galaxy ◽  
Absorption Lines ◽  
The Galaxy

As is known, a striking peculiarity of the radio galaxy NGC 4486 is the presence of a small and very bright ‘jet’ in its central part. As it seems to us, the key to the understanding of the nature of the radio galaxy NGC 4486 is the purely continuous spectrum of the above jet, where not even a slightest trace or emission or absorption lines is present.

scholarly journals “E+A” Galaxies: Environment and Evolution

1999 ◽  
Vol 186 ◽  
pp. 125-131
Author(s):  
Ann I. Zabludoff
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Morphological Characteristics ◽  
Absorption Lines ◽  
Evolutionary Track ◽  
Star Forming ◽  
Blue Star ◽  
The Galaxy ◽  
Important Approach ◽  
Critical Link

One important approach to the study of galaxy evolution is to identify those galaxies whose spectral and/or morphological characteristics suggest that they are in transition. For example, “E+A” galaxies, which have strong Balmer absorption lines and no significant [OII] emission, are generally interpreted as post-starburst galaxies in which the star formation ceased within the last ~ Gyr (Fig. 1). This transition between a star forming and non-star forming state is a critical link in any galaxy evolution model in which a blue, star forming disk galaxy evolves into a SO or elliptical. Another possible evolutionary track is that the star formation in an “E+A” resumes at some later time, if enough gas remains in the galaxy after its starburst ends. Given this ambiguity, it is important to investigate (1) the environment's role in “E+A” evolution, (2) the stellar and gas morphologies of “E+A”s, (3) the likely progenitors of “E+A”s, and (4) how common the “E+A” phase is in the evolution of galaxies.

scholarly journals 36. On the nature of the emission from the Galaxy NGC4486

1957 ◽  
Vol 4 ◽  
pp. 205-207 ◽  
Author(s):  
I. S. Shklovsky
Keyword(s):  
Continuous Spectrum ◽  
Radio Galaxy ◽  
Absorption Lines ◽  
The Galaxy

It is well known that the radio galaxy NGC4486 has as a striking peculiarity a small and very bright ‘jet’ in its central part. It seems to us that the key to the understanding of the nature of this radio galaxy is the purely continuous spectrum of the jet, where not even a slight trace of emission or absorption lines is present.

Cross-Correlation Techniques for the determination of Galaxy Redshifts

1980 ◽  
Vol 4 (1) ◽  
pp. 77-80
Author(s):  
R. W. Hunstead
Keyword(s):  
Linear Response ◽  
Cross Correlation ◽  
Absorption Lines ◽  
The Galaxy ◽  
Correlation Techniques ◽  
Subjective Estimates ◽  
Absorption Features

Most of the galaxy redshifts currently available in the literature have been measured from photographic spectra and are generally based on subjective estimates of the position of the narrow absorption features. In using only the few prominent absorption lines, most of the light from the galaxy is discarded. With the advent of digital linear-response detectors it is possible to obtain accurate and objective redshifts by cross-correlating all or part of the galaxy spectrum with a template galaxy of known redshift (Tonry and Davis 1979, Kelton 1980 and references therein).

scholarly journals Interstellar sodium and Galactic structure. A high-resolution survey

1985 ◽  
Vol 106 ◽  
pp. 325-328
Author(s):  
E. Maurice ◽  
A. Ardeberg ◽  
H. Lindgren
Keyword(s):  
High Resolution ◽  
Spectral Resolution ◽  
Absorption Lines ◽  
High Spectral Resolution ◽  
Line Of Sight ◽  
Substantial Part ◽  
Galactic Rotation ◽  
Interstellar Gas ◽  
Interstellar Clouds ◽  
The Galaxy

Observation of absorption lines produced by interstellar gas is a straight-forward way to determine column densities and velocities along the line of sight of interstellar clouds. In practice, peculiar motions often mask galactic rotation and/or cause line blending. We have made a study of absorption lines of interstellar sodium covering a substantial part of the Galaxy at extremely high spectral resolution.

scholarly journals The Future for UV Spectroscopy of the ISM at High Resolution

2005 ◽  
Vol 13 ◽  
pp. 802-804 ◽  
Author(s):  
Edward B. Jenkins
Keyword(s):  
High Resolution ◽  
Uv Spectroscopy ◽  
Absorption Lines ◽  
Basic Principles ◽  
The Future ◽  
The Galaxy ◽  
Wavelength Resolution ◽  
High Wavelength

AbstractIn the post-HST era, advanced missions for performing UV spectroscopy must excel in many ways. We must not overlook the importance of high wavelength resolution for investigating absorption lines from gas systems in the Galaxy and beyond. We consider here some basic principles on this topic, both scientific and technical.

scholarly journals Theoretical Aspects of Galaxy Dynamics Using Planetary Nebulae

2003 ◽  
Vol 209 ◽  
pp. 615-616
Author(s):  
Anne Mathieu
Keyword(s):  
Planetary Nebulae ◽  
Elliptical Galaxies ◽  
Emission Lines ◽  
Absorption Lines ◽  
Dark Halo ◽  
Galaxy Dynamics ◽  
The Galaxy ◽  
Stellar Body

The dynamics of the outer regions of elliptical galaxies is still poorly known. Their lack of gas means that it is not possible to use the usual optical and 21cm emission lines to determine the kinematics out to large radii, and the faintness of their stellar body means that data calculated using absorption lines are limited to the inner part of the galaxy. It is only by measuring the kinematics out to several optical scalelengths that one gets any unambiguous measure of the dark halo properties (Kent 1986).

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