- ID:
- ivo://CDS.VizieR/J/AJ/143/130
- Title:
- VIJH light curves of the X-Ray binary GX 339-4
- Short Name:
- J/AJ/143/130
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the optical/infrared (O/IR) light curve of the black hole X-ray binary GX 339-4 collected at the SMARTS 1.3m telescope from 2002 to 2010. During this time the source has undergone numerous state transitions including hard-to-soft state transitions when we see large changes in the near-IR flux accompanied by modest changes in optical flux, and three rebrightening events in 2003, 2005, and 2007 after GX 339-4 transitioned from the soft state to the hard. All but one outburst show similar behavior in the X-ray hardness-intensity diagram. We show that the O/IR colors follow two distinct tracks that reflect either the hard or soft X-ray state of the source. Thus, either of these two X-ray states can be inferred from O/IR observations alone. From these correlations we have constructed spectral energy distributions of the soft and hard states. During the hard state, the near-IR data have the same spectral slope as simultaneous radio data when GX 339-4 was in a bright optical state, implying that the near-IR is dominated by a non-thermal source, most likely originating from jets. Non-thermal emission dominates the near-IR bands during the hard state at all but the faintest optical states, and the fraction of non-thermal emission increases with increasing optical brightness. The spectral slope of the optical bands indicate that a heated thermal source is present during both the soft and hard X-ray states, even when GX 339-4 is at its faintest optical state. We have conducted a timing analysis of the light curve for the hard and soft states and find no evidence of a characteristic timescale within the range of 4-230days.
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Search Results
- ID:
- ivo://CDS.VizieR/II/343
- Title:
- VIKING catalogue data release 2
- Short Name:
- II/343
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The VIKING survey with VISTA (ESO programme ID 179.A-2004) is a wide area (eventually 1500 sq.degrees), intermediate-depth (5-sigma detection limit J=21 on Vega system) near-infrared imaging survey, in the five broadband filters Z, Y, J, H, Ks. The planned sky coverage is at high galactic latitudes, and includes two main stripes 70x10{deg}^2^ each: one in the South Galactic cap near Dec~-30{deg}, and one near Dec~0{deg} in the North galactic cap; in addition, there are two smaller outrigger patches called GAMA09 and CFHLS-W1. Science goals include z>6.5 quasars, extreme brown dwarfs, and multiwavelength coverage and identifications for a range of other imaging surveys, notably VST-KIDS and Herschel-ATLAS. This second public data release of VIKING data covers all of the highest quality data taken between the start of the survey (12th of November 2009) and the end of Period 92 (30th September 2013). This release supersedes the first release (VIKING and VIKING CAT published 28.06.2013 and 16.12.2013 respectively) as it includes improved CASU processing (V1.3) that gives better tile grouting and zero point corrections This release contains 396 tiles with coverage in all five VIKING filters, 379 of which have a deep co-add in J, and an additional 81 with at least two filters where the second OB has not been executed yet or one filter in an OB was poor quality. These 477 fields cover a total of ~690 square degrees and the resulting catalogues include a total of 46,270,162 sources (including low-reliability single-band detections). The imaging and catalogues (both single-band and band-merged) total 839.3GB. The coverage in each of the five sub-areas is not completely contiguous but any inter-tile gaps are relatively small. More details can be found in the accompanying documentation: viking_cat_dr2.pdf
- ID:
- ivo://CDS.VizieR/II/329
- Title:
- VIKING catalogue data release 1
- Short Name:
- II/329
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The VIKING survey with VISTA (ESO programme ID 179.A-2004) is a wide area (eventually 1500 sq.degrees), intermediate-depth (5-sigma detection limit J=21 on Vega system) near-infrared imaging survey, in the five broadband filters Z, Y, J, H, Ks. The planned sky coverage is at high galactic latitudes, and includes two main stripes 70x10{deg}^2^ each: one in the South Galactic cap near Dec~-30{deg}, and one near Dec~0{deg} in the North galactic cap; in addition, there are two smaller outrigger patches called GAMA09 and CFHLS-W1. Science goals include z>6.5 quasars, extreme brown dwarfs, and multiwavelength coverage and identifications for a range of other imaging surveys, notably VST-KIDS and Herschel-ATLAS. This first public data release of data taken between the 12th of November 2009 and the 13th of February 2011 includes 151 tiles with complete coverage in all five VIKING filters (55 in GAMA09/12/14, 91 in SGP and 5 in CFHLS-W1) i.e. 226 square degrees, and includes approximately 14,773,385 total sources (including low-reliability single-band detections) and the imaging and source lists total 314.4GB. The coverage in each of the five sub-areas is not completely contiguous but any inter-tile gaps are relatively small. More details can be found in the accompanying documentation: viking_cat_dr1.pdf
- ID:
- ivo://CDS.VizieR/J/ApJ/563/629
- Title:
- VIK' photometry and redshifts of galaxy clusters
- Short Name:
- J/ApJ/563/629
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze photometry and spectroscopy of a sample of 63 clusters at 0.3<=z<=0.9 drawn from the Las Campanas Distant Cluster Survey to empirically constrain models of cluster galaxy evolution. Our data originate from a variety of telescopes and instruments. The candidate galaxy clusters are identified using drift-scan images and techniques described briefly below for context but in full detail by Gonzalez et al. (2001, Cat. <J/ApJS/137/117>).
- ID:
- ivo://CDS.VizieR/J/ApJ/566/103
- Title:
- VIK' photometry and redshifts of galaxy clusters
- Short Name:
- J/ApJ/566/103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the influence of environment on brightest cluster galaxy (BCG) evolution using a sample of 63 clusters at 0.3<=z<=0.9 drawn primarily from the Las Campanas Distant Cluster Survey and follow-up V, I, and K' photometry. Our data originate from a variety of telescopes and instruments. The cluster sample and observations used here stem from deep optical and infrared follow-up imaging of a small subset of the full catalog that was obtained to aid in the classification of candidates and to develop photometric redshift indicators.
- ID:
- ivo://CDS.VizieR/J/ApJ/475/445
- Title:
- VIK photometry of faint field galaxies
- Short Name:
- J/ApJ/475/445
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We combine deep K-band (W. M. Keck Telescope) with V- and I-band (New Technology Telescope) observations of two "blank" high Galactic latitude fields, surveying a total of ~2arcmin^2^. The K-band number-magnitude counts continue to rise above K~22mag, reaching surface densities of few x10^5^deg^-2^. The slope for the galaxy counts is approximately [dlog(N)/dmag].deg^-2^=0.23+/-0.02 over the range 18-23mag. While this slope is consistent with other recent deep K-band surveys, there is a definite scatter in the normalisations by about a factor of 2. In particular, our normalisation is ~2x greater than the galaxy counts reported by Djorgovski et al. in 1995 (1995ApJ...438L..13D). Optical near-infrared color-magnitude and color-color diagrams for all objects detected in the V+I+K image are plotted and discussed in the context of grids of Bruzual-Charlot isochrone synthesis galaxy evolutionary models. The colors of most of the observed galaxies are consistent with a population drawn from a broad redshift distribution. A few galaxies at K~19-20 are red in both colors (V-I>3; I-K>2, consistent with being early-type galaxies having undergone a burst of star formation at z>5 and viewed at z~1. At K>20, we find several (approximately eight) "red outlier" galaxies with I-K>4 and V-I<2.5, whose colors are difficult to mimic by a single evolving or nonevolving stellar population at any redshift unless they either have quite low metallicity or are highly reddened. We compare the data against the evolutionary tracks of second-burst ellipticals and against a grid of models that does not constrain galaxy ages to a particular formation redshift. The red outliers' surface density is several per square arcminute, which is so high that they are probably common objects of low luminosity L<L*. Whether these are low-metallicity, dusty dwarf galaxies, or old galaxies at high redshift, they are curious and merit spectroscopic follow-up.
- ID:
- ivo://CDS.VizieR/J/A+A/443/413
- Title:
- VIKs photometry of NGC4365 globular clusters
- Short Name:
- J/A+A/443/413
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This table lists VIKs photometry for compact objects in the giant Virgo elliptical NGC 4365. The majority of these objects are globular clusters. V and I magnitudes are measured on images taken with the FORS1 instrument on the ESO Very Large Telescope, while the K magnitudes are from the SOFI imager on the ESO New Technology Telescope. No correction for foreground extinction has been applied to the photometry in the table.
- ID:
- ivo://CDS.VizieR/J/ApJ/839/52
- Title:
- Vi' LCs and RVs of the EB star TYC 5227-1023-1
- Short Name:
- J/ApJ/839/52
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The orbit and physical parameters of the previously unsolved double-lined eclipsing binary Tyc 5227-1023-1, discovered during the search for RR Lyr variable candidate members of the Aquarius stream, are derived using high-resolution echelle spectroscopy and V,i' photometry. A synthetic spectral analysis of both components has been performed, yielding metallicity [M/H]=-0.63+/-0.11 for both stars and a temperature for the secondary that is in close agreement with the one from the orbital solution, while the temperature of the primary is determined from photometry (T_1_=6350K). The masses and radii (M_1_=0.96+/-0.02, M_2_=0.84+/-0.01M_{sun}_, R_1_=1.39+/-0.01, R_2_=0.98+/-0.01R_{sun}_) reveal that both stars have already slightly evolved away from the main-sequence band, having an age of about 7Gyr, and the results of the synthetic spectral analysis support the claim of corotation with the orbital motion. The radial velocity of the system is -60+/-2km/s, while its distance, computed from orbital parameters and the derived reddening E_B-V_=0.053, is 496+/-35pc. Even though Tyc 5227-1023-1 was initially treated as a possible member of the Aquarius stream, the results presented here disagree with reported values for this ancient structure and suggest a likely membership of the thick disk.
- ID:
- ivo://CDS.VizieR/J/A+A/550/A93
- Title:
- VI light curves of V383 Sco
- Short Name:
- J/A+A/550/A93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The system V383 Sco was discovered to be an eclipsing binary star at the beginning of the twentieth century. This system has one of the longest orbital periods known (13.5yr) and was initially classified as a zeta Aur-type eclipsing variable. It was then forgotten about for decades, with no progress made in understanding it. This study provides a detailed look at the system V383 Sco, using new data obtained before, during and after the last eclipse, which occurred in 2007/8. There was a suspicion that this system could be similar to eclipsing systems with extensive dusty disks like EE Cep and epsilon Aur. This and other, alternative hypotheses are considered here. The All Sky Automated Survey (ASAS-3) V and I light curves have been used to examine apparent magnitude and colour changes. Low- and high- resolution spectra have been obtained and used for spectral classification, to analyse spectral line profiles, as well as to determine the reddening, radial velocities and the distance to the system. The spectral energy distribution (SED) was analysed using all available photometric and spectroscopic data. Using our own original numerical code, we performed a very simplified model of the eclipse, taking into account the pulsations of one of the components. The low-resolution spectrum shows apparent traces of molecular bands, characteristic of an M-type supergiant. The presence of this star in the system is confirmed by the SED, by a strong dependence of the eclipse depth on the photometric bands, and by the nature of pulsational changes. The presence of a very low excitation nebula around the system has been inferred from [OI] 6300{AA} emission in the high-resolution spectrum. Analysis of the radial velocities, reddening, and period-luminosity relation for Mira-type stars imply a distance to the V383 Sco system of 8.4+/-0.6kpc. The distance to the nearby V381 Sco is 6.4+/-0.8kpc. The very different and oppositely directed radial velocities of these two systems (89.8km/s vs -178.8km/s) seem to be in agreement with a bulge/bar kinematic model of the Galactic centre and inconsistent with purely circular motion. Conclusions. We have found strong evidence for the presence of a pulsating M-type supergiant in the V383 Sco system. This supergiant periodically obscures the much more luminous F0 I-type star, causing the deep (possibly total) eclipses which vary in duration and shape.
- ID:
- ivo://CDS.VizieR/J/A+A/590/A21
- Title:
- Vilnius photometry near Sh 2-205
- Short Name:
- J/A+A/590/A21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of CCD photometry in the seven-color Vilnius system for 302 stars in the 12x12 arcmin area in the vicinity of the dark cloud TGU H942 P7. Observational data were obtained in 2015-2016 with the 1.8m VATT telescope of the Vatican observatory on Mt Graham, Arizona. Using the Koenig & Leisawitz (2014ApJ...791..131K) classification scheme we identified 88 YSOs in this area. The majority of them are concentrated in dust clump P7 and the infrared cluster FSR 655. The other compact group of YSOs is located at RA=03:54:56, DEC=+53:45. These stars are probably members of small infrared cluster which we call SCB1.
