The Oxygen Abundance of Nearby Galaxies from Sloan Digital Sky Survey Spectra

ABSTRACT We compare the oxygen abundance (O/H) of the narrow-line regions (NLRs) of Seyfert 2 AGNs obtained through strong-line methods and from direct measurements of the electron temperature (Te-method). The aim of this study is to explore the effects of the use of distinct methods on the range of metallicity and on the mass–metallicity relation of active galactic nuclei (AGNs) at low redshifts (z ≲ 0.4). We used the Sloan Digital Sky Survey (SDSS) and NASA/IPAC Extragalactic Database (NED) to selected optical (3000 < λ(Å) < 7000) emission line intensities of 463 confirmed Seyfert 2 AGNs. The oxygen abundances of the NLRs were estimated using the theoretical Storchi-Bergmann et al. calibrations, the semi-empirical N2O2 calibration, the Bayesian H ii-Chi-mistry code and the Te-method. We found that the oxygen abundance estimations via the strong-line methods differ from each other up to ∼0.8 dex, with the largest discrepancies in the low-metallicity regime ($\rm 12+\log (O/H) \: \lesssim \: 8.5$). We confirmed that the Te-method underestimates the oxygen abundance in NLRs, producing unreal subsolar values. We did not find any correlation between the stellar mass of the host galaxies and the metallicity of their AGNs. This result is independent of the method used to estimate Z.

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Oxygen abundance in the Sloan Digital Sky Survey

Astronomy and Astrophysics ◽

10.1051/0004-6361:20054524 ◽

2006 ◽

Vol 453 (2) ◽

pp. 487-492 ◽

Cited By ~ 22

Author(s):

F. Shi ◽

X. Kong ◽

F. Z. Cheng

Keyword(s):

Sloan Digital Sky Survey ◽

Oxygen Abundance ◽

Sky Survey

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Peculiar motions of the gas at the centre of the barred galaxy UGC 4056

Astronomy and Astrophysics ◽

10.1051/0004-6361/201935897 ◽

2019 ◽

Vol 628 ◽

pp. A55 ◽

Cited By ~ 1

Author(s):

I. A. Zinchenko ◽

L. S. Pilyugin ◽

F. Sakhibov ◽

E. K. Grebel ◽

A. Just ◽

...

Keyword(s):

Rotation Velocity ◽

Colour Index ◽

Sloan Digital Sky Survey ◽

Galactocentric Distance ◽

Circular Velocity ◽

Sky Survey ◽

The Galaxy ◽

Nearby Galaxies ◽

Gas Response ◽

Gaseous Disc

We derive the circular velocity curves of the gaseous and stellar discs of UGC 4056, a giant barred galaxy with an active galactic nucleus (AGN). We analyse UGC 4056 using the 2D spectroscopy obtained within the framework of the Mapping Nearby Galaxies at APO (MaNGA) survey. Using images and the colour index g − r from the Sloan Digital Sky Survey (SDSS), we determined the tilt of the galaxy, which allows us to conclude that the galaxy rotates clockwise with trailing spiral arms. We found that the gas motion at the central part of the UGC 4056 shows peculiar features. The rotation velocity of the gaseous disc shows a bump within around three kiloparsecs while the rotation velocity of the stellar disc falls smoothly to zero with decreasing galactocentric distance. We demonstrate that the peculiar radial velocities in the central part of the galaxy may be caused by the inflow of the gas towards the nucleus of the galaxy. The unusual motion of the gas takes place at the region with the AGN-like radiation and can be explained by the gas response to the bar potential.

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Detecting galaxy–filament alignments in the Sloan Digital Sky Survey III

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz539 ◽

2019 ◽

Vol 485 (2) ◽

pp. 2492-2504 ◽

Cited By ~ 11

Author(s):

Yen-Chi Chen ◽

Shirley Ho ◽

Jonathan Blazek ◽

Siyu He ◽

Rachel Mandelbaum ◽

...

Keyword(s):

Narrow Range ◽

Stellar Mass ◽

Sloan Digital Sky Survey ◽

Nearby Galaxy ◽

Matter Distribution ◽

Direction Parallel ◽

Significant Alignment ◽

Sky Survey ◽

Nearby Galaxies ◽

Web Reconstruction

Abstract Previous studies have shown the filamentary structures in the cosmic web influence the alignments of nearby galaxies. We study this effect in the LOWZ sample of the Sloan Digital Sky Survey using the ‘Cosmic Web Reconstruction' filament catalogue. We find that LOWZ galaxies exhibit a small but statistically significant alignment in the direction parallel to the orientation of nearby filaments. This effect is detectable even in the absence of nearby galaxy clusters, which suggests it is an effect from the matter distribution in the filament. A non-parametric regression model suggests that the alignment effect with filaments extends over separations of 30–40 Mpc. We find that galaxies that are bright and early-forming align more strongly with the directions of nearby filaments than those that are faint and late-forming; however, trends with stellar mass are less statistically significant, within the narrow range of stellar mass of this sample.

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Calculation of velocity dispersion of the nearby galaxies using different stellar template libraries

Serbian Astronomical Journal ◽

10.2298/saj1080057l ◽

2010 ◽

pp. 57-69

Author(s):

Ana Lalovic

Keyword(s):

Reasonable Agreement ◽

Velocity Dispersion ◽

Signal To Noise Ratio ◽

Sloan Digital Sky Survey ◽

Signal To Noise ◽

Method Of Calculation ◽

Sky Survey ◽

Best Fitting ◽

Nearby Galaxies ◽

Spectral Libraries

We present the central velocity dispersion measurements of the nearby galaxies from the Sloan Digital Sky Survey (SDSS). Using the sample from the paper by Ho et al. 2009, we have selected 23 galaxies for which we calculate the velocity dispersion. We have used the Penalized Pixel-Fitting code (Cappellari and Emsellem2004) to measure the velocity dispersion throughout the four chosen spectral regions: (3800,4568)?A, (4568,5336)?A, (5336,6104) and (6104,6872)?A. In all these regions, we have separately calculated dispersions and corresponding errors. We found that the measured values may vary with the change of spectral region, but, if weighted properly with the measure of the goodness of the fit, the final results will be shifted coloser to those for the best fitting regions. We have also tested how the use of different spectral libraries (Miles, Valdes and Elodie databases) influences measurements and we showed that they do not affect measurements much. However, Elodie stellar library introduces the smallest errors in the velocity dispersion and it is the most stable throughout all four spectral regions. For these reasons it should be used preferentially when dealing with the SDSS spectra. We compare the results with the above mentioned paper and find a reasonable agreement. The agreement with the dispersions available in the HyperLeda database is very poor. The best agreement is obtained with SDSS measurements. We believe that our measurements are useful since SDSS velocity dispersions measurements are not available for many galaxies and the method of calculation of the velocity dispersion outlined in this work enables calculation of velocity dispersion for any galaxy. Of course, spectra with signal-to-noise ratio below 20 should be taken with caution.

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