scholarly journals Verification of Photometric Parallaxes with Gaia DR2 Data

Galaxies ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 7
Author(s):  
Oleg Malkov ◽  
Sergey Karpov ◽  
Dana Kovaleva ◽  
Sergey Sichevsky ◽  
Dmitry Chulkov ◽  
...  
Keyword(s):  
Galaxy Evolution ◽  
High Latitude ◽  
Interstellar Extinction ◽  
Photometric Data ◽  
Sloan Digital Sky Survey ◽  
Combined Analysis ◽  
Luminosity Class ◽  
Sky Survey ◽  
Gaia Dr2

Results of comparison of Gaia DR2 parallaxes with data derived from a combined analysis of 2MASS (Two Micron All-Sky Survey), SDSS (Sloan Digital Sky Survey), GALEX (Galaxy Evolution Explorer), and UKIDSS (UKIRT Infrared Deep Sky Survey) surveys in four selected high-latitude | b | > 48° sky areas are presented. It is shown that multicolor photometric data from large modern surveys can be used for parameterization of stars closer than 4400 pc and brighter than g S D S S = 19 . m 6 , including estimation of parallax and interstellar extinction value. However, the stellar luminosity class should be properly determined.

scholarly journals Verification of photometric parallaxes with Gaia DR2 data

2018 ◽  
Author(s):  
Oleg Malkov ◽  
Sergey Karpov ◽  
Dana Kovaleva ◽  
Sergey Sichevsky ◽  
Dmitry Chulkov ◽  
...  
Keyword(s):  
High Latitude ◽  
Interstellar Extinction ◽  
Photometric Data ◽  
Combined Analysis ◽  
Gaia Dr2

We present the result of comparison of Gaia DR2 parallaxes and photometry with data derived from a combined analysis of 2MASS, SDSS, GALEX, and UKIDSS surveys in four selected high-latitude sky areas. We have shown that, under certain circumstances, multicolor photometric data from large modern surveys can be successfully used for parameterization of stars, including estimation of distance and interstellar extinction value.

scholarly journals Effect of bars on evolution of SDSS spiral galaxies

2020 ◽  
Vol 494 (4) ◽  
pp. 5839-5850
Author(s):  
Minbae Kim ◽  
Yun-Young Choi ◽  
Sungsoo S Kim
Keyword(s):  
Galaxy Evolution ◽  
Velocity Dispersion ◽  
Sufficient Conditions ◽  
Central Star ◽  
Sloan Digital Sky Survey ◽  
Causal Connection ◽  
Limited Sample ◽  
Massive Black Hole ◽  
Barred Galaxies ◽  
Sky Survey

ABSTRACT We explore the significance of bars in triggering central star formation (SF) and active galactic nucleus (AGN) activity for spiral galaxy evolution using a volume-limited sample with 0.020 < z < 0.055, Mr < −19.5, and σ > 70 km s−1 selected from Sloan Digital Sky Survey Data Release 7. On a central SF rate–σ plane, we measure the fraction of galaxies with strong bars in our sample and also the AGN fractions for barred and non-barred galaxies, respectively. The comparison between the bar and AGN fractions reveals a causal connection between the two phenomena of SF quenching and AGN activity. A massive black hole and abundant gas fuels are sufficient conditions to trigger AGNs. We infer that the AGNs triggered by satisfying the two conditions drive the strong AGN feedback, suddenly suppressing the central SF and leaving the SF sequence. We find that in galaxies where either of the two conditions is not sufficient, bars are a great help for the AGN triggering, accelerating the entire process of evolution, which is particularly evident in pseudo-bulge galaxies. All of our findings are obtained only when plotted in terms of their central velocity dispersion and central SFR (not galactic scale SFR), indicating that the AGN-driven SF quenching is confined in the central kpc region.

scholarly journals The Distribution of Main Belt Asteroids with Featureless Spectra from the Sloan Digital Sky Survey Photometry

2009 ◽  
Vol 5 (S263) ◽  
pp. 237-239
Author(s):  
Anderson O. Ribeiro ◽  
Fernando Roig
Keyword(s):  
Spectroscopic Data ◽  
Moving Objects ◽  
Photometric Data ◽  
Sloan Digital Sky Survey ◽  
Spectral Slope ◽  
Main Belt ◽  
Absorption Bands ◽  
Sky Survey ◽  
The Mean

AbstractIn this work, we propose to analyse the existence of possible correlations between the taxonomic classes of asteroids showing featureless spectra –i.e. a flat continuum with no absorption bands– and their orbital properties. We compute the mean spectral slope of 14 753 asteroids using the photometric data from the Sloan Digital Sky survey Moving Objects Catalog (SDSS-MOC4). Although the quality of these data is not comparable in resolution to the spectroscopic data, the amount of observations in the SDSS-MOC4 is more than 20 times larger that in the available spectral databases. This allows us to obtain a statistically significant result.

scholarly journals SFR Relation with Galaxy Environment and Colour at z between 0.03 and 0.1

2006 ◽  
Vol 2 (S235) ◽  
pp. 234-235
Author(s):  
Premana W. Premadi ◽  
A. Sitti Maryam
Keyword(s):  
Galaxy Evolution ◽  
Sloan Digital Sky Survey ◽  
Emission Lines ◽  
Limited Sample ◽  
Data Set ◽  
Star Forming ◽  
Diagnostic Diagram ◽  
Sky Survey ◽  
Data Release ◽  
Galaxy Environment

This work is a preliminary result of our attempt to examine the use of SFR in the study of galaxy evolution. For this purpose we use the Sloan Digital Sky Survey Data Release 2 (SDSS DR2) Abazajian et al. (2004) and the SFR Catalogue generated from this data set by Brinchmann et al. (2004) and Kaufmann et al. (2003). Following Kewley et al. (2001) we use the Diagnostic Diagram, log ([OIII]/Hβ) vs log ([NII]/Hα), to separate the star forming galaxies from other emission lines sources such as AGN. Choosing only those with S/N > 3 out of the Brinchmann et al. (2004) catalogue, we arrive at about 200 thousand galaxies as our starting SFR subsample. With 0.05 < z < 0.22 and limit at r = 17.77, the subsample can be used to reconstruct the properties of a volume limited sample of galaxies with M* = 6 1010Modot. We benefit from the fact that Brinchmann et al. (2004) SFR Catalogue has already been aperture-corrected using the likelihood distribution P(SFR/Li/colour) scheme. For the environment, we use the data generated by Kaufmann et al. (2003), and arrive at about 40 thousand target galaxies. In this work the environment is characterised by the number (N=0-30) of neighbouring galaxies within a projected radius of 2 Mpc and velocity di.erence of 500km/s from each target galaxy, and the magnitude limit is 14.5 < r < 17.77.

scholarly journals Identifying Circumgalactic Medium Absorption in QSO Spectra: A Bayesian Approach

2021 ◽  
Vol 923 (1) ◽  
pp. 44
Author(s):  
Jennifer E. Scott ◽  
Emileigh S. Shoemaker ◽  
Colin D. Hamill
Keyword(s):  
Bayesian Methods ◽  
Statistical Approach ◽  
Hubble Space Telescope ◽  
Spectroscopic Studies ◽  
Photometric Data ◽  
Sloan Digital Sky Survey ◽  
Sky Survey ◽  
The Galaxy ◽  
Circumgalactic Medium

Abstract We present a study of candidate galaxy–absorber pairs for 43 low-redshift QSO sightlines (0.06 < z < 0.85) observed with the Hubble Space Telescope/Cosmic Origins Spectrograph that lie within the footprint of the Sloan Digital Sky Survey with a statistical approach to match absorbers with galaxies near the QSO lines of sight using only the SDSS Data Release 12 photometric data for the galaxies, including estimates of their redshifts. Our Bayesian methods combine the SDSS photometric information with measured properties of the circumgalactic medium to find the most probable galaxy match, if any, for each absorber in the line-of-sight QSO spectrum. We find ∼630 candidate galaxy–absorber pairs using two different statistics. The methods are able to reproduce pairs reported in the targeted spectroscopic studies upon which we base the statistics at a rate of 72%. The properties of the galaxies comprising the candidate pairs have median redshift, luminosity, and stellar mass, all estimated from the photometric data, z = 0.13, L = 0.1L *, and log ( M * / M ⊙ ) = 9.7 . The median impact parameter of the candidate pairs is ∼430 kpc, or ∼3.5 times the galaxy virial radius. The results are broadly consistent with the high Lyα covering fraction out to this radius found in previous studies. This method of matching absorbers and galaxies can be used to prioritize targets for spectroscopic studies, and we present specific examples of promising systems for such follow-up.

scholarly journals Compact galaxies and the size–mass galaxy distribution from a colour-selected sample at 0.04 < z < 0.15 supplemented by ugrizYJHK photometric redshifts

2020 ◽  
Vol 500 (2) ◽  
pp. 1557-1574
Author(s):  
Ivan K Baldry ◽  
Tricia Sullivan ◽  
Raffaele Rani ◽  
Sebastian Turner
Keyword(s):  
Galaxy Evolution ◽  
High Redshift ◽  
Sample Selection ◽  
Distribution Functions ◽  
Sloan Digital Sky Survey ◽  
Photometric Redshifts ◽  
Galaxy Distribution ◽  
Sky Survey ◽  
Galaxy Sample ◽  
Compact Galaxies

ABSTRACT The size–mass galaxy distribution is a key diagnostic for galaxy evolution. Massive compact galaxies are potential surviving relics of a high-redshift phase of star formation. Some of these could be nearly unresolved in Sloan Digital Sky Survey (SDSS) imaging and thus not included in galaxy samples. To overcome this, a sample was selected from the combination of SDSS and UKIRT Infrared Deep Sky Survey (UKIDSS) photometry to r &lt; 17.8. This was done using colour–colour selection, and then by obtaining accurate photometric redshifts (photo-z) using scaled flux matching (SFM). Compared to spectroscopic redshifts (spec-z), SFM obtained a 1σ scatter of 0.0125 with only 0.3 per cent outliers (|Δln (1 + z)| &gt; 0.06). A sample of 163 186 galaxies was obtained with 0.04 &lt; z &lt; 0.15 over $2300\, {\rm deg}^2$ using a combination of spec-z and photo-z. Following Barro et al. log Σ1.5 = log M* − 1.5log r50, maj was used to define compactness. The spectroscopic completeness was 76 per cent for compact galaxies (log Σ1.5 &gt; 10.5) compared to 92 per cent for normal-sized galaxies. This difference is primarily attributed to SDSS ‘fibre collisions’ and not the completeness of the main galaxy sample selection. Using environmental overdensities, this confirms that compact quiescent galaxies are significantly more likely to be found in high-density environments compared to normal-sized galaxies. By comparison with a high-redshift sample from 3D-HST, log Σ1.5 distribution functions show significant evolution, with this being a compelling way to compare with simulations such as EAGLE. The number density of compact quiescent galaxies drops by a factor of about 30 from z ∼ 2 to log (n/Mpc−3) = − 5.3 ± 0.4 in the SDSS–UKIDSS sample. The uncertainty is dominated by the steep cut off in log Σ1.5, which is demonstrated conclusively using this complete sample.

scholarly journals Galaxy Zoo: Outreach and Science Hand in Hand

2012 ◽  
Vol 10 (H16) ◽  
pp. 689-691 ◽  
Author(s):  
Karen L. Masters ◽  
Keyword(s):  
Galaxy Evolution ◽  
Citizen Science ◽  
Public Engagement ◽  
Hubble Space Telescope ◽  
Effective Means ◽  
Scientific Output ◽  
Sloan Digital Sky Survey ◽  
The Public ◽  
Data Intensive ◽  
Sky Survey

AbstractGalaxy Zoo (www.galaxyzoo.org) is familiar to many as a hugely successful public engagement project. Hundreds of thousands of members of the public have contributed to Galaxy Zoo which collects visual classifications of galaxies in Sloan Digital Sky Survey and Hubble Space Telescope images. Galaxy Zoo has inspired a suite of similar Citizen Science projects known as “The Zooniverse“ (www.zooniverse.org) which now has well over half a million participants. Galaxy Zoo has also shown itself, in a series of peer reviewed papers, to be a fantastic database for the study of galaxy evolution. In this invited talk I described how that public engagement via citizen science is not only an effective means of outreach from data intensive surveys, but if done right can and must also increase the scientific output of the survey.

scholarly journals Spatial Orientations of Angular Momentum Vectors of Galaxies in Supercluster S [195+027+0022] and Substructure

2021 ◽  
Vol 7 (2) ◽  
pp. 81-88
Author(s):  
J. R. Malla ◽  
W. Saurer ◽  
B. Aryal
Keyword(s):  
Galaxy Evolution ◽  
Azimuthal Angle ◽  
Three Dimensional ◽  
Simulation Method ◽  
Position Angle ◽  
Sloan Digital Sky Survey ◽  
Chi Square ◽  
Rotation Axes ◽  
Sky Survey ◽  
The Galaxy

This paper presents an analysis of the spin vector orientations of SDSS (Sloan Digital Sky Survey) galaxies in the Supercluster S [195+027+0022] using the seventh data release (2008 October). By using the spectroscopic database of galaxies, identified number density map in the region of Superclusters. Several density enhancements are observed, suggesting the possibility of substructure in the Supercluster. Two-dimensional observed parameters that we received from the database are used to compute three-dimensional galaxy rotation axes by applying `position angle-inclination' method. Apply the selection effects by performing the random simulation method. The expected distribution curves are obtained from the simulation. Chi-square, auto-correlation, and Fourier tests are used to examine non-random effects in the polar and azimuthal angle distributions of the galaxy rotation axes. To check these results with the different galaxy evolution models namely Hierarchy, Primordial, and Pancake model. The result supports the Hierarchy model.

Classification and Characterization of Objects from the Galaxy Evolution Explorer Survey and the Sloan Digital Sky Survey

2005 ◽  
Vol 619 (1) ◽  
pp. L27-L30 ◽  
Author(s):  
Luciana Bianchi ◽  
Mark Seibert ◽  
Wei Zheng ◽  
David A. Thilker ◽  
Peter G. Friedman ◽  
...  
Keyword(s):  
Galaxy Evolution ◽  
Sloan Digital Sky Survey ◽  
Sky Survey ◽  
The Galaxy
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