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2501. OGLE2-TR-L9 g'r'i'z' light curves
ID:
ivo://CDS.VizieR/J/A+A/522/A29
Title:
OGLE2-TR-L9 g'r'i'z' light curves
Short Name:
J/A+A/522/A29
Date:
21 Oct 2021
Publisher:
CDS
Description:
Repeated observations of exoplanet transits allow us to refine the planetary parameters and probe them for any time dependent variations. In particular deviations of the period from a strictly linear ephemeris, transit timing variations (TTVs), can indicate the presence of additional bodies in the planetary system. Aims: Our goal was to reexamine the largely unstudied OGLE2-TR-L9 system with high cadence, multi-color photometry in order to refine the planetary parameters and probe the system for TTVs. From our analysis we find that the semi-major axis and the inclination differ from the previously published values. With the newly observed transits, we were able to refine the ephemeris to 2454492.80008(+/-0.00014) +2.48553417(+/-6.4)x10^-7^E. The newly derived parameters are a=0.0418(+/-0.0015)AU, r_p_=1.67(+/-0.05) R_j_, and inc=82.47{deg}(+/-0.12), differing significantly in a and inc from the previously published values. Within our data, we find indications for TTVs.
2502. OGLE UBVI phot. in Baade's Window
ID:
ivo://CDS.VizieR/J/AcA/49/319
Title:
OGLE UBVI phot. in Baade's Window
Short Name:
J/AcA/49/319
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present UBVI photometry for 8530 stars in Baade's Window obtained during the OGLE-II microlensing survey. Among these are over one thousand red clump giants. 1391 of them have photometry with errors smaller than 0.04, 0.06, 0.12, and 0.20 mag in the I, V, B, and U-band, respectively. We constructed a map of interstellar reddening. The corrected colors of the red clump giants: (U-B)_0_, (B-V)_0_, and (V-I)_0_ are very well correlated, indicating that a single parameter determines the observed spread of their values, reaching almost 2mag in the (U-B)_0_. It seems most likely that heavy element content is the dominant parameter, but it is possible that another parameter: the age (or mass) of a star moves it along the same trajectory in the color-color diagram as the metallicity. The current ambiguity can be resolved with spectral analysis, and our catalog may be useful as a finding list of red clump giants. We point out that these K giants are more suitable for a fair determination of the distribution of metallicity than brighter M giants. We also present a compilation of UBVI data for 308 red clump giants near the Sun, for which Hipparcos parallaxes are more accurate than 10%. Spectral analysis of their metallicity may provide information about the local metallicity distribution as well as the extent to which mass (age) of these stars affects their colors.
2503. OJ 287 far-infrared photometry
ID:
ivo://CDS.VizieR/J/A+A/610/A74
Title:
OJ 287 far-infrared photometry
Short Name:
J/A+A/610/A74
Date:
21 Oct 2021
Publisher:
CDS
Description:
The blazar OJ 287 has shown a ~~12 year quasi-periodicity over more than a century, in addition to the common properties of violent variability in all frequency ranges. It is the strongest known candidate to have a binary singularity in its central engine. We aim to better understand the different emission components by searching for correlated variability in the flux over four decades of frequency measurements. We combined data at frequencies from the millimetric to the visible to characterise the multifrequency light curve in April and May 2010. This includes the only photometric observations of OJ 287 made with the Herschel Space Observatory: five epochs of data obtained over 33 days at 250, 350, and 500um with Herschel-SPIRE. Although we find that the variability at 37GHz on timescales of a few weeks correlates with the visible to near-IR spectral energy distribution (SED), there is a small degree of reddening in the continuum at lower flux levels that is revealed by the decreasing rate of decline in the light curve at lower frequencies. However, we see no clear evidence that a rapid flare detected in the light curve during our monitoring in the visible to near-IR light curve is seen either in the Herschel data or at 37GHz, suggesting a low-frequency cut-off in the spectrum of such flares. We see only marginal evidence of variability in the observations with Herschel over a month, although this may be principally due to the poor sampling. The spectral energy distribution between 37 GHz and the visible can be characterised by two components of approximately constant spectral index: a visible to far-IR component of spectral index {alpha}=-0.95, and a far-IR to millimetric spectral index of {alpha}=0.43. There is no evidence of an excess of emission that would be consistent with the 60um dust bump found in many active galactic nuclei.
2504. OJ 287 flux & polarization during 2016 outburst
ID:
ivo://CDS.VizieR/J/ApJ/835/275
Title:
OJ 287 flux & polarization during 2016 outburst
Short Name:
J/ApJ/835/275
Date:
21 Oct 2021
Publisher:
CDS
Description:
The gamma-ray blazar OJ 287 was in a high activity state during 2015 December-2016 February. Coinciding with this high brightness state, we observed this source for photometry on 40 nights in R-band and for polarimetry on nine epochs in UBV RI bands. During the period of our observations, the source brightness varied from 13.20+/-0.04 mag to 14.98+/-0.04mag and the degree of polarization (P) fluctuated between 6.0%+/-0.3% and 28.3%+/-0.8% in R-band. Focusing on intranight optical variability (INOV), we find a duty cycle of about 71% using {chi}^2^-statistics, similar to that known for blazars. From INOV data, the shortest variability timescale is estimated to be 142+/-38min, yielding a lower limit of the observed Doppler factor {delta}_0_=1.17, the magnetic field strength B<=3.8G, and the size of the emitting region R_s_<2.28x10^14^cm. On internight timescales, a significant anticorrelation between R-band flux and P is found. The observed P at U-band is generally larger than that observed at longer-wavelength bands, suggesting a wavelength-dependent polarization. Using V-band photometric and polarimetric data from Steward Observatory obtained during our monitoring period, we find a varied correlation between P and V-band brightness. While an anticorrelation is sometimes seen between P and V-band magnitude, no correlation is seen at other times, thereby suggesting the presence of more than one short-lived shock component in the jet of OJ 287.
2505. Old stellar systems (globulars to ellipticals)
ID:
ivo://CDS.VizieR/J/MNRAS/389/1924
Title:
Old stellar systems (globulars to ellipticals)
Short Name:
J/MNRAS/389/1924
Date:
21 Oct 2021
Publisher:
CDS
Description:
Elliptical galaxies and globular clusters (GCs) have traditionally been regarded as physically distinct entities due to their discontinuous distribution in key scaling diagrams involving size, luminosity and velocity dispersion. Recently this distinctness has been challenged by the discovery of stellar systems with mass intermediate between those of GCs and dwarf ellipticals (such as ultracompact dwarfs and dwarf galaxy transition objects). Here we examine the relationship between the virial and stellar mass for a range of old stellar systems, from GCs to giant ellipticals, and including such intermediate-mass objects (IMOs). Improvements on previous work in this area include the use of (i) near-infrared magnitudes from the Two Micron All Sky Survey (2MASS), (ii) aperture corrections to velocity dispersions, (iii) homogeneous half-light radii and (iv) accounting for the effects of non-homology in galaxies.
2506. OmegaWINGS BV photometry of galaxy clusters
ID:
ivo://CDS.VizieR/J/A+A/581/A41
Title:
OmegaWINGS BV photometry of galaxy clusters
Short Name:
J/A+A/581/A41
Date:
21 Oct 2021
Publisher:
CDS
Description:
The WIde-field Nearby Galaxy-cluster Survey (WINGS) is a wide-field and multiwavelength survey of 76 galaxy clusters in the local Universe. The sample consists of all clusters at 0.04<z<0.07 in both hemispheres at Galactic latitude |b|>20 selected from the ROSAT X-ray-Brightest Abell-type Cluster Sample, the Brightest Cluster Sample, and its extension. The original WINGS survey is based on B and V imaging for the 76 clusters over a 34 by 34 arcminute field of view taken with the Wide Field Cameras on the INT and the 2.2m MPG/ESO telescopes. With the aim to cover the virial region and extend out into the infall region, we have obtained GTO OmegaCAM imaging in the B, and V bands over 1 by 1 degree for 45 fields covering 46 WINGS clusters. We present the Johnson B- and V-band OmegaCAM photometry of 46 WINGS clusters. With a median seeing of 1 arcsecond in both B- and V-bands, our 25-minutes exposures in each band typically reach the 50% completeness level at V=23.1mag.
2507. O-M stars model atmospheres
ID:
ivo://CDS.VizieR/J/A+A/333/231
Title:
O-M stars model atmospheres
Short Name:
J/A+A/333/231
Date:
21 Oct 2021
Publisher:
CDS
Description:
Broad band colors and bolometric corrections in the Johnson-Cousins-Glass system (Bessell, 1990PASP..102.1181B; Bessell & Brett, 1988PASP..100.1134B) have been computed from synthetic spectra from new model atmospheres of Kurucz (1995a, priv. comm.), Castelli (1997, priv. comm.), Plez, Brett & Nordlund (1992A&A...256..551P), Plez (1995-97, priv. comm.), and Brett (1995A&A...295..736B, 1995A&AS..109..263B). These atmospheres are representative of larger grids that are currently being completed. We discuss differences between the different grids and compare theoretical color-temperature relations and the fundamental color temperature relations derived from: (a) the infrared-flux method (IRFM) for A-K stars (Blackwell & Lynas-Gray 1994A&A...282..899B; Alonso et al. 1996A&AS..117..227A) and M dwarfs (Tsuji et al. 1996A&A...305L...1T); (b) lunar occultations (Ridgway et al. 1980ApJ...235..126R) and (c) Michelson interferometry (Di Benedetto & Rabbia 1987A&A...188..114D; Dyck et al. 1996AJ....111.1705D; Perrin et al. 1998A&A...331..619P) for K-M giants, and (d) eclipsing binaries for M dwarfs. We also compare color-color relations and color-bolometric correction relations and find good agreement except for a few colors. The more realistic fluxes and spectra of the new model grids should enable accurate population synthesis models to be derived and permit the ready calibration of non-standard photometric passbands. As well, the theoretical bolometric corrections and temperature-color relations will permit reliable transformation from observed color magnitude diagrams to theoretical HR diagrams.
2508. ONC low-mass stars photometry
ID:
ivo://CDS.VizieR/J/AJ/121/1676
Title:
ONC low-mass stars photometry
Short Name:
J/AJ/121/1676
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have photometrically monitored ~3600 young, low-mass stars in four 45'x45' fields in the outer Orion Nebula cluster, surrounding but not including the Trapezium region.
2509. One-side head-tail (OHT) galaxies from FIRST & SDSS
ID:
ivo://CDS.VizieR/J/ApJS/254/30
Title:
One-side head-tail (OHT) galaxies from FIRST & SDSS
Short Name:
J/ApJS/254/30
Date:
21 Oct 2021
Publisher:
CDS
Description:
One-side head-tail (OHT) galaxies are radio galaxies with a peculiar shape. They usually appear in galaxy clusters, but they have never been cataloged systematically. We design an automatic procedure to search for them in the Faint Images of the Radio Sky at Twenty-Centimeters source catalog and compile a sample with 115 HT candidates. After cross-checking with the Sloan Digital Sky Survey photometric data and catalogs of galaxy clusters, we find that 69 of them are possible OHT galaxies. Most of them are close to the center of galaxy clusters. The lengths of their tails do not correlate with the projection distance to the center of the nearest galaxy clusters, but show weak anticorrelation with the cluster richness, and are inversely proportional to the radial velocity differences between clusters and host galaxies. Our catalog provides a unique sample to study this special type of radio galaxies.
2510. On the nature of small galaxy systems
ID:
ivo://CDS.VizieR/J/MNRAS/481/2458
Title:
On the nature of small galaxy systems
Short Name:
J/MNRAS/481/2458
Date:
21 Oct 2021
Publisher:
CDS
Description:
We aim at defining homogeneous selection criteria of small galaxy systems in order to build catalogues suitable to compare main properties of pairs, triplets, and groups with four or more members. To this end we use spectroscopic and photometric Sloan Digital Sky Survey (SDSS) data to identify systems with a low number of members. We study global properties of these systems and the properties of their member galaxies finding that galaxies in groups are systematically redder and with lower star formation activity indicators than galaxies in pairs which have a higher fraction of star-forming galaxies. Triplet galaxies present intermediate trends between pairs and groups. We also find an enhancement of star formation activity for galaxies in small systems with companions closer than 100kpc, irrespective of the number of members. We have tested these analyses on SDSS mock catalogues derived from the Millennium simulation, finding as conservative thresholds 76 per cent completeness and a contamination of 23 per cent in small galaxy systems, when considering an extreme case of incompleteness due to fiber collisions. Nevertheless, we also found that the results obtained are not likely affected by projection effects. Our studies suggest that an extra galaxy in a system modify the properties of the member galaxies. In pairs, galaxy-galaxy interactions increase gas density and trigger starbursts. However, repeated interactions in triplets and groups can generate gas stripping, turbulence, and shocks quenching the star formation in these systems.