scholarly journals FLAIR II Spectroscopy of Two DENIS J Band Galaxy Samples

2001 ◽  
Vol 18 (3) ◽  
pp. 232-242 ◽  
Author(s):  
Gary A. Mamon ◽  
Quentin A. Parker ◽  
Dominique Proust
Keyword(s):  
Uv Light ◽  
Emission Lines ◽  
Galactic Latitude ◽  
Low Latitude ◽  
High Galactic Latitude ◽  
Cluster Of Galaxies ◽  
Redshift Survey ◽  
Galaxy Redshift ◽  
Emission Line Galaxies ◽  
Optical Surveys

AbstractAs a pilot survey for the forthcoming 6dF Galaxy Redshift Survey, spectroscopy of galaxies selected in the 1.2 micron J waveband with the DENIS imaging survey was performed at the UKST using the FLAIR II multi-object spectroscope. Sixty-nine galaxy redshifts were obtained in a high galactic latitude field and an additional 12 redshifts in a low galactic latitude (b = 17˚), obscured field. This spectroscopic followup of NIR selected galaxies illustrates the feasibility of obtaining redshifts with optical spectra on galaxies selected at much longer wavelengths. It validated a very preliminary algorithm for star/galaxy separation for high galactic latitude DENIS objects, with 99% reliability for J <13.9. The FLAIR II redshifts are in excellent agreement with those, previously published, of 20 common galaxies. However, the FLAIR II redshift determinations presented here required substantially longer integration times to achieve 90% completeness than expected from previous optical surveys at comparable depth. This is mainly due to a degradation in overall fibre throughput due to known problems with ageing of the prism–cement–fibre interface with exposure to UV light. In comparison to our high galactic latitude field, our low latitude (high extinction) field required 2.5 times more exposure time for less than 50% of successful redshift measurements.Among the J ≤ 13.9 galaxies with measured redshifts, only 376% display emission lines, in comparison with 60% of emission line galaxies in optical samples of comparable depth. These galaxies are, on average, half a magnitude bluer in B-J than galaxies of the same luminosity without emission lines. We confirm a previous optically-based result that the fraction of galaxies with emission lines increases rapidly with decreasing galaxy luminosity. The J band luminosity function is estimated. Our high latitude field displays a concentration of galaxies at cz ≲ 38 000 km s−1 suggesting a possible supercluster.A radial velocity is reported for a galaxy lying near the projected centre of the Abell 1434 cluster of galaxies, for which no cluster redshift is currently available.

scholarly journals Spectral Characteristics of the 2dFGRS–NVSS Galaxies

2000 ◽  
Vol 17 (3) ◽  
pp. 234-240 ◽  
Author(s):  
C. A. Jackson ◽  
D. M. Londish
Keyword(s):  
Spectral Characteristics ◽  
Line Ratio ◽  
Emission Lines ◽  
Sky Survey ◽  
Show Evidence ◽  
Redshift Survey ◽  
Galaxy Redshift ◽  
Narrow Emission

AbstractWe have analysed the 2dF spectra of a sample of galaxies common to the 2dF Galaxy Redshift Survey (2dFGRS, Colless 1999) and the NRAO VLA Sky Survey (NVSS, Condon et al. 1998). Our sample comprises 88 galaxies selected by Sadler et al. (1999) from 30 2dFGRS fields observed in 1998. In this paper we discuss how this and future, much larger, samples of 2dFGRS–NVSS galaxies can be interpreted via analysis of those galaxies with strong narrow emission lines. Using diagnostic line ratio measurements, we confirm the majority of the eyeball classifications of Sadler et al. (1999), although many galaxies show evidence of being ‘composite’ galaxies—mixtures of AGN plus starburst components.

scholarly journals The Subaru FMOS galaxy redshift survey (FastSound). V. Intrinsic alignments of emission-line galaxies at z ∼ 1.4

2018 ◽  
Vol 70 (3) ◽  
Author(s):  
Motonari Tonegawa ◽  
Teppei Okumura ◽  
Tomonori Totani ◽  
Gavin Dalton ◽  
Karl Glazebrook ◽  
...  
Keyword(s):  
Emission Line ◽  
Redshift Survey ◽  
Galaxy Redshift ◽  
Emission Line Galaxies

scholarly journals The Center for Astrophysics Redshift Survey

1983 ◽  
Vol 104 ◽  
pp. 167-173
Author(s):  
M. Davis ◽  
J. Huchra ◽  
D. Latham
Keyword(s):  
Northern Hemisphere ◽  
Mass Density ◽  
Sample Volume ◽  
Galactic Latitude ◽  
Clusters Of Galaxies ◽  
Data Set ◽  
High Galactic Latitude ◽  
Local Supercluster ◽  
Redshift Survey ◽  
Local Mean

We have completed the survey of radial velocities for all 2400 galaxies brighter than 14.5 at high galactic latitude in the northern hemisphere. This data set has already been used to derive a good measure of the local mean mass density, describe the overdensity and the dynamics of the local supercluster and to analyse the dynamics of groups and clusters of galaxies within the sample volume.

scholarly journals Using the 6dF Galaxy Redshift Survey to Detect Gravitationally-lensed Quasars

2001 ◽  
Vol 18 (2) ◽  
pp. 195-197 ◽  
Author(s):  
Daniel J. Mortlock ◽  
Michael J. Drinkwater
Keyword(s):  
United Kingdom ◽  
Infrared Spectroscopy ◽  
Near Infrared ◽  
Emission Lines ◽  
Schmidt Telescope ◽  
Galaxy Surveys ◽  
The United Kingdom ◽  
Redshift Survey ◽  
Galaxy Redshift

AbstractIt is possible to detect gravitationally-lensed quasars spectroscopically if the spectra obtained during galaxy surveys are searched for the presence of quasar emission lines. The up-coming 6 degree Field (6dF) redshift survey on the United Kingdom Schmidt Telescope will involve obtaining ~105 spectra of near-infrared selected galaxies to a magnitude limit of K = 13. Applying previously developed techniques implies that at least one lens should be discovered in the 6dF survey, but that as many as ten could be found if quasars typically have BJ – K ~ 8. In this model there could be up to fifty lensed quasars in the sample, but most of them could only be detected by infrared spectroscopy.

scholarly journals The [O ii]λ3727/Hα ratio of emission-line galaxies in the 2dF Galaxy Redshift Survey

2005 ◽  
Vol 362 (4) ◽  
pp. 1143-1156 ◽  
Author(s):  
M. Mouhcine ◽  
I. Lewis ◽  
B. Jones ◽  
F. Lamareille ◽  
S. J. Maddox ◽  
...  
Keyword(s):  
Emission Line ◽  
Redshift Survey ◽  
Galaxy Redshift ◽  
Emission Line Galaxies

scholarly journals The Subaru FMOS galaxy redshift survey (FastSound). II. The emission line catalog and properties of emission line galaxies

2016 ◽  
Vol 68 (3) ◽  
pp. 47 ◽  
Author(s):  
Hiroyuki Okada ◽  
Tomonori Totani ◽  
Motonari Tonegawa ◽  
Masayuki Akiyama ◽  
Gavin Dalton ◽  
...  
Keyword(s):  
Emission Line ◽  
Redshift Survey ◽  
Galaxy Redshift ◽  
Emission Line Galaxies

scholarly journals SAO 244567 (HEN1357): A Post-Agb Star which has turned into a Planetary Nebula within the last 20 years

1998 ◽  
Vol 11 (1) ◽  
pp. 358-358
Author(s):  
M. Parthasarathy
Keyword(s):  
Planetary Nebula ◽  
Far Infrared ◽  
Central Star ◽  
Terminal Velocity ◽  
Galactic Latitude ◽  
Iras Source ◽  
High Galactic Latitude ◽  
Alpha Emission ◽  
Early Type Star ◽  
Emission Strength

SAO 244567 (Henl357) (IRAS 17119-5926) is a high galactic latitude (1 = 331°, b = −12°) early type star, originally classified as a B or A type H-alpha emission line star by Henize (1976). It is an IRAS source with far infrared colours similar to planetary nebulae. The IUE ultraviolet spectra obtained during the last eight years show that the central star is rapidly evolving. It is found that the central star of this young PN has faded by a factor of 3 within the last seven eight years. The terminal velocity of the stellar wind has decreased from −3500 km/sec in 1988 to almost zero in 1994. In 1988 the C IV (1550A) line which was a P-Cygni profile with strong absorption component had almost vanished by 1994. The CIII] 1909A emission strength increased markedly within 4 years from 1988 to 1992. The optical spectra obtained since 1990 shows very clearly only the nebular spectrum which is very similar to that of low excitation planetary nebula. The optical spectrum of SAO 244567 obtained in 1971 shows that it was a post-AGB B 1 or B2 supergiant at that time. This result shows that SAO 244567 has turned into a planetary nebula within the last 20 years. Recently Bobrowsky (1994) obtained narrowband optically resolved images in both H-beta and [OIII] 5007A with the HST planetary camera which revealed a well resolved nebula of size 2 seconds of arc. In this paper we discuss the recent new results.

scholarly journals Unexpected circular radio objects at high Galactic latitude

2021 ◽  
Vol 38 ◽  
Author(s):  
Ray P. Norris ◽  
Huib T. Intema ◽  
Anna D. Kapińska ◽  
Bärbel S. Koribalski ◽  
Emil Lenc ◽  
...  
Keyword(s):  
Galactic Latitude ◽  
High Galactic Latitude ◽  
Square Kilometre Array ◽  
Pilot Survey ◽  
The Universe

Abstract We have found a class of circular radio objects in the Evolutionary Map of the Universe Pilot Survey, using the Australian Square Kilometre Array Pathfinder telescope. The objects appear in radio images as circular edge-brightened discs, about one arcmin diameter, that are unlike other objects previously reported in the literature. We explore several possible mechanisms that might cause these objects, but none seems to be a compelling explanation.

scholarly journals THE DEEP2 GALAXY REDSHIFT SURVEY: THE VORONOI-DELAUNAY METHOD CATALOG OF GALAXY GROUPS

2012 ◽  
Vol 751 (1) ◽  
pp. 50 ◽  
Author(s):  
Brian F. Gerke ◽  
Jeffrey A. Newman ◽  
Marc Davis ◽  
Alison L. Coil ◽  
Michael C. Cooper ◽  
...  
Keyword(s):  
Galaxy Groups ◽  
Redshift Survey ◽  
Galaxy Redshift ◽  
Deep2 Galaxy Redshift Survey
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