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4711. Optical and radio data for rich Abell clusters
ID:
ivo://CDS.VizieR/J/AJ/126/119
Title:
Optical and radio data for rich Abell clusters
Short Name:
J/AJ/126/119
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present optical observations and radio continuum imaging data for a sample of rich, X-ray-bright Abell clusters at intermediate (z~0.2) redshifts. We find that the radio galaxy population varies substantially from cluster to cluster within this homogeneous sample. The spatial distribution of the high-luminosity radio galaxies (HLRGs; L1.4>10^23^W/Hz) is very different from the low-luminosity radio galaxies (LLRGs; L1.4<=10^22.75^W/Hz), with the LLRGs displaying a flat spatial distribution in contrast to the centrally peaked HLRGs. A color-morphology classification shows that the HLRGs are composed primarily of galaxies with old stellar populations, whereas the LLRGs have a much more diverse composition. We do not see a correlation between the cluster radio fraction and cluster blue fraction. However, there is a moderate anticorrelation with richness, suggesting that a rich cluster is less likely to have radio-bright galaxies, whether the radio emission is due to active galactic nuclei or star formation.
4712. Optical and radio study of Abell 2111
ID:
ivo://CDS.VizieR/J/AJ/131/2426
Title:
Optical and radio study of Abell 2111
Short Name:
J/AJ/131/2426
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an in-depth analysis of the Butcher-Oemler cluster A2111, including new optical spectroscopy plus a deep Very Large Array (VLA) radio continuum observation. These are combined with optical imaging from the Sloan Digital Sky Survey (SDSS) to assess the activity and properties of member galaxies. Prior X-ray studies have suggested A2111 to be a head-on cluster merger, a dynamical state that might be connected to the high level of activity inferred from its blue fraction. We are able to directly assess this claim, using our spectroscopic data to identify 95 cluster members among 196 total galaxy spectra. We are able to detect 175 optical sources from the SDSS in our VLA radio data, of which 35 have redshift information.
4713. Optical and ultraviolet photometry of SN 2012fr
ID:
ivo://CDS.VizieR/J/AJ/148/1
Title:
Optical and ultraviolet photometry of SN 2012fr
Short Name:
J/AJ/148/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
Extensive optical and UltraViolet (UV) observations of the type Ia supernova (SN Ia) 2012fr are presented in this paper. It has a relatively high luminosity, with an absolute B-band peak magnitude of about -19.5mag and a smaller post-maximum decline rate than normal SNe Ia (e.g., {Delta}m_15_(B)=0.85+/-0.05mag). Based on the UV and optical light curves, we derived that a ^56^Ni mass of about 0.88M_{sun}_ was synthesized in the explosion. The earlier spectra are characterized by noticeable high-velocity features of Si II {lambda}6355 and Ca II with velocities in the range of ~22000-25000km/s. At around the maximum light, these spectral features are dominated by the photospheric components which are noticeably narrower than normal SNe Ia. The post-maximum velocity of the photosphere remains almost constant at ~12000km/s for about one month, reminiscent of the behavior of some luminous SNe Ia like SN 1991T. We propose that SN 2012fr may represent a subset of the SN 1991T-like SNe Ia viewed in a direction with a clumpy or shell-like structure of ejecta, in terms of a significant level of polarization reported in Maund et al. (2013MNRAS.433L..20M).
4714. Optical and UV colors of Coma galaxies
ID:
ivo://CDS.VizieR/J/MNRAS/421/2982
Title:
Optical and UV colors of Coma galaxies
Short Name:
J/MNRAS/421/2982
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present and analyse optical and ultraviolet (UV) colours for passive and optically-red Coma cluster galaxies for which we have spectroscopic age and element abundance estimates. Our sample of 150 objects covers a wide range in mass, from giant ellipticals down to the bright end of the dwarf-galaxy regime. Galaxies with ongoing star formation have been removed using strict H{alpha} emission-line criteria. We focus on the colours FUV-i, NUV-i, FUV-NUV, u*-g and g-i. We find that all of these colours are correlated with both luminosity and velocity dispersion at the >5{sigma} level, with FUV-i and FUV-NUV becoming bluer with increasing 'mass' while the other colours become redder. We perform a purely empirical analysis to assess what fraction of the variation in each colour can be accounted for by variations in the average stellar populations, as traced by the optical spectra.
4715. Optical and UV follow-up of 1ES 1927+654
ID:
ivo://CDS.VizieR/J/ApJ/883/94
Title:
Optical and UV follow-up of 1ES 1927+654
Short Name:
J/ApJ/883/94
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study the sudden optical and ultraviolet (UV) brightening of 1ES1927+654, which until now was known as a narrow-line active galactic nucleus (AGN). 1ES 1927+654 was part of the small and peculiar class of "true Type-2" AGNs that lack broad emission lines and line-of-sight obscuration. Our high-cadence spectroscopic monitoring captures the appearance of a blue, featureless continuum, followed several weeks later by the appearance of broad Balmer emission lines. This timescale is generally consistent with the expected light travel time between the central engine and the broadline emission region in (persistent) broadline AGN. Hubble Space Telescope spectroscopy reveals no evidence for broad UV emission lines (e.g., CIV{lambda}1549, CIII]{lambda}1909, MgII{lambda}2798), probably owing to dust in the broadline emission region. To the best of our knowledge, this is the first case where the lag between the change in continuum and in broadline emission of a "changing look" AGN has been temporally resolved. The nature and timescales of the photometric and spectral evolution disfavor both a change in line-of-sight obscuration and a change of the overall rate of gas inflow as driving the drastic spectral transformations seen in this AGN. Although the peak luminosity and timescales are consistent with those of tidal disruption events seen in inactive galaxies, the spectral properties are not. The X-ray emission displays a markedly different behavior, with frequent flares on timescales of hours to days, and will be presented in a companion publication.
4716. Optical and UV photometry of SN 2013dy
ID:
ivo://CDS.VizieR/J/AJ/151/125
Title:
Optical and UV photometry of SN 2013dy
Short Name:
J/AJ/151/125
Date:
21 Oct 2021
Publisher:
CDS
Description:
Extensive and independent observations of Type Ia supernova (SNIa) SN2013dy are presented, including a larger set of UBVRI photometry and optical spectra from a few days before the peak brightness to ~200days after explosion, and ultraviolet (UV) photometry spanning from t~-10days to t~+15days refers to the B band maximum. The peak brightness (i.e., M_B_=-19.65+/-0.40mag; L_max_=[1.95+/-0.55]*10^43^/ergs) and the mass of synthesized ^56^Ni (i.e., M(^56^Ni)=0.90+/-0.26M_{Sun}_) are calculated, and they conform to the expectation for an SNIa with a slow decline rate (i.e., {Delta}m_15_(B)=0.90+/-0.03mag). However, the near infrared (NIR) brightness of this SN (i.e., M_H_=-17.33+/-0.30mag) is at least 1.0mag fainter than usual. Besides, spectroscopy classification reveals that SN2013dy resides on the border of "core normal" and "shallow silicon" subclasses in the Branch et al. classification scheme, or on the border of the "normal velocity" SNeIa and 91T/99aa-like events in the Wang et al. system. These suggest that SN2013dy is a slow-declining SNIa located on the transitional region of nominal spectroscopic subclasses and might not be a typical normal sample of SNeIa.
4717. Optical brightness of 3 ROSAT Seyfert galaxies
ID:
ivo://CDS.VizieR/J/A+A/310/384
Title:
Optical brightness of 3 ROSAT Seyfert galaxies
Short Name:
J/A+A/310/384
Date:
21 Oct 2021
Publisher:
CDS
Description:
The printed version of this paper describes the X-ray and optical properties of four new active galaxies discovered in the ROSAT All-Sky Survey. While one object (RX J1257.5+2412) is identified as a BL Lac object, the other three (RX J1239.3+2431, RX J1225.7+2055, and RX J1250.2+1923) are narrow line Seyfert 1 galaxies. Three of these four objects are bright enough to be studied on archival photographic plates of Sonneberg Observatory. The present list contains the individual brightness measurements of these objects all of which turned out to be variable on timescales of weeks to years. Some lightcurves (long-term as well as short-term) are given in the printed version.
4718. Optical catalog of AKARI NEP-wide survey
ID:
ivo://CDS.VizieR/J/ApJS/190/166
Title:
Optical catalog of AKARI NEP-wide survey
Short Name:
J/ApJS/190/166
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the source catalog and the properties of the B-, R-, and I-band images obtained to support the AKARI North Ecliptic Pole Wide (NEP-Wide) survey. The NEP-Wide is an AKARI infrared imaging survey of the north ecliptic pole covering a 5.8deg^2^ area over 2.5-6um wavelengths. The optical imaging data were obtained at the Maidanak Observatory in Uzbekistan using the Seoul National University 4kx4k Camera on the 1.5m telescope. These images cover 4.9deg^2^ where no deep optical imaging data are available. Our B-, R-, and I-band data reach the depths of ~23.4, ~23.1, and ~22.3mag(AB) at 5{sigma}, respectively. The source catalog contains 96460 objects in the R band, and the astrometric accuracy is about 0.15" at 1{sigma} in each RA and DEC direction. These photometric data will be useful for many studies including identification of optical counterparts of the infrared sources detected by AKARI, analysis of their spectral energy distributions from optical through infrared, and the selection of interesting objects to understand the obscured galaxy evolution.
4719. Optical counterparts of Chandra GBS sources
ID:
ivo://CDS.VizieR/J/ApJS/214/10
Title:
Optical counterparts of Chandra GBS sources
Short Name:
J/ApJS/214/10
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present optical light curves of variable stars consistent with the positions of X-ray sources identified with the Chandra X-ray Observatory for the Chandra Galactic Bulge Survey (GBS). Using data from the Mosaic-II instrument on the Blanco 4m Telescope at CTIO, we gathered time-resolved photometric data on timescales from ~2hr to 8 days over the 3/4 of the X-ray survey containing sources from the initial GBS catalog. Among the light curve morphologies we identify are flickering in interacting binaries, eclipsing sources, dwarf nova outbursts, ellipsoidal variations, long period variables, spotted stars, and flare stars. Eighty-seven percent of X-ray sources have at least one potential optical counterpart. Twenty-seven percent of these candidate counterparts are detectably variable; a much greater fraction than expected for randomly selected field stars, which suggests that most of these variables are real counterparts. We discuss individual sources of interest, provide variability information on candidate counterparts, and discuss the characteristics of the variable population.
4720. Optical counterparts of X-ray sources in OGLE
ID:
ivo://CDS.VizieR/J/AcA/62/133
Title:
Optical counterparts of X-ray sources in OGLE
Short Name:
J/AcA/62/133
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a sample of 209 variable objects - very likely optical counterparts to the X-ray sources detected in the direction of the Galactic center by the Galactic Bulge Survey (GBS) carried out with the Chandra satellite. The variable sources were found in the databases of the OGLE long term survey monitoring regularly the Galactic bulge since 1992. The counterpart candidates were searched based on the X-ray source position in the radius of 3.9 arcsec.