- ID:
- ivo://CDS.VizieR/J/MNRAS/420/2190
- Title:
- ECDFS sources with radio counterparts
- Short Name:
- J/MNRAS/420/2190
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In order to trace the instantaneous star formation rate (SFR) at high redshift, and thus help in understanding the relation between the different emission mechanisms related to star formation, we combine the recent 4-Ms Chandra X-ray data and the deep Very Large Array radio data in the Extended Chandra Deep Field-South region. We find 268 sources detected both in the X-ray and radio bands. The availability of redshifts for ~95 per cent of the sources in our sample allows us to derive reliable luminosity estimates and the intrinsic properties from X-ray analysis for the majority of the objects.
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- ID:
- ivo://CDS.VizieR/J/A+A/462/795
- Title:
- Echelle spectra of 10 bright asteroids
- Short Name:
- J/A+A/462/795
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Echelle spectra of 10 bright asteroids are presented and compared against an observed twilight spectrum and a computed Solar spectrum. Spectra covering a 2130{AA} spectral range centered on 5785{AA} are of high resolving power and high signal to noise ratio. We compare detailed properties of spectral lines and not albedo variations. It is shown that the normalized Solar and asteroid spectra are identical except for radial velocity (RV) shifts which can be predicted at accuracy level of 1m/s. So asteroids are proposed as new and extremely accurate radial velocity standards. Predicted and measured RVs of observed asteroids match within the limits of accuracy of the instrument. There are numerous absorption lines in the reflected Solar spectrum. This allows a direct mapping of the resolving power of a spectrograph between and along echelle spectral orders. Thus asteroid spectra can be used to test the wavelength calibration and resolving power of spectrographs on the ground as well as in space, including the Gaia mission of ESA.
- ID:
- ivo://CDS.VizieR/J/A+A/528/A21
- Title:
- Echelle spectroscopy of {delta} Vel
- Short Name:
- J/A+A/528/A21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The nearby multiple system delta Velorum contains a widely detached eclipsing binary and a third component. We take advantage of this system offering the opportunity to determine the set of fundamental parameters (masses, luminosities, and radii) of three coeval stars with sufficient precision to test models of stellar evolution. Extensive high-resolution spectroscopy is analyzed by the broadening function technique to provide the first spectroscopic orbit of the eclipsing pair. Simultaneous analysis of the spectroscopic data and the SMEI satellite light curve is performed to provide astrophysical parameters for the components. We use a modified Roche model assuming an eccentric orbit and asynchronous rotation. The observations show that components of the eclipsing pair rotate at about two-thirds of the break-up velocity, which excludes any chemical peculiarity and results in a non-uniform surface brightness. Although the inner orbit is eccentric, no apsidal motion is seen during the SMEI photometric observations. For the inner orbit, the orbital parameters are eccentricity e=0.290, longitude of the periastron passage omega=109{deg}, and inclination 89.0{deg}. The component masses of M(Aa)=2.53+/-0.11M_{sun}_, M(Ab)=2.37+/-0.10M_{sun}_, and M(B)~1.5M_{sun}_ combined with the inferred radii of the Aa and Ab components indicate that the eclipsing pair has already left the main sequence and that the estimated age of the system is about 400Myr.
- ID:
- ivo://CDS.VizieR/J/AJ/159/189
- Title:
- Eclipse timings for 9 contact binaries
- Short Name:
- J/AJ/159/189
- Date:
- 08 Dec 2021
- Publisher:
- CDS
- Description:
- In this paper, we present the first light curve synthesis and orbital period change analysis of nine contact binaries around the short-period limit. It is found that all these systems are W-subtype contact binaries. One of them is a medium contact system while the others are shallow contact ones. Four of them manifest obvious O'Connell effect explained by a dark spot or hot spot on one of the component stars. Third light was detected in three systems. By investigating orbital period variations, we found that four of the targets display a secular period decrease while the others exhibit a long-term period increase. The secular period decrease is more likely caused by angular-momentum loss while the long-term period increase is due to mass transfer from the less massive component to the more massive one. Based on the statistic of 19 ultrashort-period contact binaries with known orbital period changes, we found that seven of them display long-term decrease (three of them also exhibit cyclic variations), ten of them manifest long-term increase while two of them only show cyclic variation, and that most of them are shallow contact binaries supporting the long timescale angular-momentum loss theory suggested by Stepien. For the three deep contact systems, we found that they are probably triple systems. The tertiary companion plays an essential role during their formation and evolution.
- ID:
- ivo://CDS.VizieR/J/AJ/146/58
- Title:
- Eclipse timings for NGC 6819-259
- Short Name:
- J/AJ/146/58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze extensive BVR_c_I_c_time-series photometry and radial-velocity measurements for WOCS 40007 (Auner 259; KIC 5113053), a double-lined detached eclipsing binary and a member of the open cluster NGC 6819. Utilizing photometric observations from the 1m telescope at Mount Laguna Observatory and spectra from the WIYN 3.5m telescope, we measure precise and accurate masses (~1.6% uncertainty) and radii (~0.5%) for the binary components. In addition, we discover a third star orbiting the binary with a period greater than 3000days using radial velocities and Kepler eclipse timings. Because the stars in the eclipsing binary are near the cluster turnoff, they are evolving rapidly in size and are sensitive to age. With a metallicity of [Fe/H]=+0.09 +/-0.03, we find the age of NGC 6819 to be about 2.4Gyr from color-magnitude diagram (CMD) isochrone fitting and 3.1+/-0.4Gyr by analyzing the mass-radius (M-R) data for this binary. The M-R age is above previous determinations for this cluster, but consistent within 1{sigma} uncertainties. When the M-R data for the primary star of the additional cluster binary WOCS 23009 is included, the weighted age estimate drops to 2.5+/-0.2Gyr, with a systematic uncertainty of at least 0.2Gyr. The age difference between our CMD and M-R findings may be the result of systematic error in the metallicity or helium abundance used in models, or due to slight radius inflation of one or both stars in the WOCS 40007 binary.
- ID:
- ivo://CDS.VizieR/J/AJ/150/1
- Title:
- Eclipse timings of 27 eclipsing binaries in the SMC
- Short Name:
- J/AJ/150/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the periods of apsidal motion for 27 early-type eclipsing binaries with high eccentricity located in the Small Magellanic Cloud. New times of minima were derived from the light curves constructed by the MACHO, Optical Gravitational Lensing Experiment (OGLE)-II, and OGLE-III survey data. The eclipse timing diagrams of the binary systems were analyzed using those timings and the elements of apsidal motions were obtained in detail for the first time. The apsidal motion periods of all systems were estimated by detailed analysis of both eclipse timings and light curves; a strong correlation value between both methods is shown. We confirm that OGLE-SMC-ECL-2194 shows the shortest known apsidal motion period of 7.1yr in a detached system with main sequence stars. Nineteen systems show intermediate apsidal motion periods between 10 and 100yr, and seven systems exhibit long apsidal periods of more than 100yr.
- ID:
- ivo://CDS.VizieR/J/AJ/149/93
- Title:
- Eclipse timings of KIC 5621294
- Short Name:
- J/AJ/149/93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the physical properties of KIC 5621294, showing light and timing variations from the Kepler photometry. Its light curve displays partial eclipses and the O'Connell effect, with Max II fainter than Max I, which was fitted quite well by applying third-body and spot effects to the system. The results indicate that the eclipsing pair is a classical Algol-type system with parameters of q=0.22, i=76.8{deg}, and {Delta}(T_1_-T_2_)=4235K, in which the detached primary component fills about 77% of its limiting lobe. Striking discrepancies exist between the primary and secondary eclipse times obtained with the method of Kwee & van Woerden. These are mainly caused by surface inhomogeneities due to spot activity detected in our light curve synthesis. The 1253 light curve timings from the Wilson-Devinney code were used for a period study. It was found that the orbital period of KIC 5621294 has varied due to periodic variation overlaid on a downward parabola. The sinusoidal variation with a period of 961days and a semi-amplitude of 22.5s most likely arises from a light-time effect due to a third component with a mass of M_3_sini_3_=46.9M_Jup_, which is in good agreement with that calculated from the light curve itself. If its orbital inclination is larger than about 40{deg}, the mass of the circumbinary object would possibly match a brown dwarf. The parabolic variation could not be fully explained by either a mass transfer between the binary components or angular momentum via magnetic braking. It is possible that the parabola may be the only observed part of a period modulation caused by the presence of another companion in a wider orbit.
- ID:
- ivo://CDS.VizieR/J/A+AS/109/447
- Title:
- Eclipsing binaries EROS catalogue
- Short Name:
- J/A+AS/109/447
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Catalogue and photometry of eclipsing binary stars in the bar of the LMC obtained from observations in two colours made during 1991-92 by the French EROS project.
- ID:
- ivo://CDS.VizieR/J/A+A/506/501
- Title:
- Eclipsing binaries in CoRoT-LRc01 field
- Short Name:
- J/A+A/506/501
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present here the list of planetary transit candidates detected in the first long run observed by CoRoT: LRc01, towards the galactic center in the direction of Aquila, which lasted from May to October 2007. We analyzed 3719 (33%) sources in the chromatic bands and 7689 in the monochromatic band. Instrumental noise and the stellar variability were treated with several detrending tools, on which subsequently several transit search algorithms were applied. Forty two sources were classified as planetary transit candidates and up to now 26 cases have been solved. One planet (CoRoT-2b) and one brown-dwarf (CoRoT-3b) have been the subjects of detailed publications.
- ID:
- ivo://CDS.VizieR/J/MNRAS/362/1006
- Title:
- Eclipsing binaries in eastern spiral arm of M31
- Short Name:
- J/MNRAS/362/1006
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of an archival survey are presented using B, V-band imaging of the eastern spiral arm of M31. Focusing on the eclipsing binary star population, a matched-filter technique has been used to identify 280 binary systems. Of these, 127 systems (98 of which are newly discovered) have sufficient phase coverage to allow accurate orbital periods to be determined. At least nine of these binaries are detached systems, which could, in principle, be used for distance determination. The light curves of the detached and other selected systems are presented along with a discussion of some of the more interesting binaries. The impact of unresolved stellar blends on these light curves is considered.