- ID:
- ivo://CDS.VizieR/J/A+A/633/A37
- Title:
- RXJ1604.3-2130A griz and JHK light curves
- Short Name:
- J/A+A/633/A37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- RX J1604.3-2130A is a young, dipper-type, variable star in the Upper Scorpius association, suspected to have an inclined inner disk with respect to its face-on outer disk. We study the eclipses to constrain the inner disk properties. We use time-resolved photometry from the Rapid Eye Mount telescope and Kepler 2 data to study the multi-wavelength variability, and archival optical and IR data to track accretion, rotation, and changes in disk structure. The observations reveal details of the structure and matter transport through the inner disk. The eclipses show 5d quasi-periodicity, with the phase drifting in time and some periods showing increased/decreased eclipse depth and frequency. Dips are consistent with extinction by slightly processed dust grains in an inclined, irregularly-shaped inner disk locked to the star through two relatively stable accretion structures. The grains are located near the dust sublimation radius (~0.09au) at the corotation radius, and can explain the shadows observed in the outer disk. The total mass (gas and dust) required to produce the eclipses and shadows is a few % of a Ceres mass. Such amount of mass is accreted/replenished by accretion in days to weeks, which explains the variability from period to period. Spitzer and WISE variability reveal variations in the dust content in the innermost disk on a few years timescale, which is consistent with small imbalances (compared to the stellar accretion rate) in the matter transport from the outer to the inner disk. A decrease in the accretion rate is observed at the times of less eclipsing variability and low mid-IR fluxes, confirming this picture. The vsini=16km/s confirms that the star cannot be aligned with the outer disk, but is likely close to equator-on and to be aligned with the inner disk. This anomalous orientation is a challenge for standard theories of protoplanetary disk formation.
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1332. RY Sct UBVR photometry
- ID:
- ivo://CDS.VizieR/J/A+A/374/638
- Title:
- RY Sct UBVR photometry
- Short Name:
- J/A+A/374/638
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The present study deals with the problem of the estimation of the orbital and physical parameters for the EB-type eclipsing binary RY Sct, based on the interpretation of new photometric U B V R observations. The light curves obtained at the Maidanak Observatory during 1979-94 show a slight asymmetry around the secondary minima and a small difference in the height of the successive maxima. The light curves are analysed in the framework of the Roche computer model (Djurasevic, 1992Ap&SS.196..241D) by applying the inverse-problem method (Djurasevic, 1992Ap&SS.197...17D) based on Marquardt's (1963, J. Soc. Ind. Appl. Math. 11(2), 431) algorithm. The analysis shows that RY Sct system is in an overcontact configuration (f_over_~33%) with q=m_2_/m_1_=m_cool_/m_hot_=3.3 and i~84.3{deg}, generating total-annular eclipses. The basic parameters of the system and of the active region are estimated for all individual U, B, V and R light curves. Our results suggested a mass exchange between the components and mass loss through the outer Lagrangian point L_3_. This could be taken as a possible mechanism in the formation of the circumstellar envelope of toroidal form lying in the orbital plane of the system.
1333. RY Tau in 1996
- ID:
- ivo://CDS.VizieR/J/A+A/341/553
- Title:
- RY Tau in 1996
- Short Name:
- J/A+A/341/553
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The T Tauri star RY Tau has increased its brightness from V=10.6mag to V=9.6mag in October-November 1996. By February-March 1997, the star has faded again to V=10.8mag. High-resolution echelle spectra of RY Tau were obtained wit h the SOFIN spectrograph at the Nordic Optical Telescope (La Palma, Spain) at lo w and high brightness levels of the star. No significant changes in the photosph eric lines, which are sensitive to temperature and gravity, were noticed. The spectral type of RY Tau is defined as G1-2IV, which in combination with photomet ric data implies A_V_=1.0-1.3mag. Polarimetric patrol of RY Tau during the fadin g of the star showed an increase of its intrinsic polarization from 0.5-1.0% at high brightness to about 2% at low brightness in the V, R and I bands. The flux radiated in H{alpha} and the IR Ca II emission lines remained about the same, in spite of the one magnitude difference in the continuum flux. These results indicate that variable obscuration of the star by circumstellar dust clo uds was responsible for the brightness change of RY Tau, and that the emission l ine source is mostly outside of the obscured region.
1334. RZ Dra
- ID:
- ivo://CDS.VizieR/J/A+A/285/459
- Title:
- RZ Dra
- Short Name:
- J/A+A/285/459
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
1335. RZ Dra BVR light curves
- ID:
- ivo://CDS.VizieR/J/AJ/140/1687
- Title:
- RZ Dra BVR light curves
- Short Name:
- J/AJ/140/1687
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new multicolor photometry for RZ Draconis, observed in 2009 at the Xinglong Station of the National Astronomical Observatories of China. By using the updated version of the Wilson-Devinney Code, the photometric-spectroscopic elements were deduced from new photometric observations and published radial velocity data.
1336. RZ Tau UBVR photometry
- ID:
- ivo://CDS.VizieR/J/A+A/343/894
- Title:
- RZ Tau UBVR photometry
- Short Name:
- J/A+A/343/894
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/ApJ/778/15
- Title:
- SAGE-SMC III. Young stellar objects
- Short Name:
- J/ApJ/778/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Spitzer Space Telescope Legacy Program SAGE-SMC allows global studies of resolved stellar populations in the SMC in a different environment than our Galaxy. Using the SAGE-SMC IRAC (3.6-8.0{mu}m) and MIPS (24 and 70{mu}m) catalogs and images combined with near-infrared (JHK_s_) and optical (UBVI) data, we identified a population of ~1000 intermediate - to high-mass young stellar objects (YSOs) in the SMC (three times more than previously known). Our method of identifying YSO candidates builds on the method developed for the Large Magellanic Cloud by Whitney et al. (2008, J/AJ/136/18) with improvements based on what we learned from our subsequent studies and techniques described in the literature. We perform (1) color-magnitude cuts based on five color-magnitude diagrams (CMDs), (2) visual inspection of multi-wavelength images, and (3) spectral energy distribution (SED) fitting with YSO models. For each YSO candidate, we use its photometry to calculate a measure of our confidence that the source is not a non-YSO contaminant, but rather a true YSO, based on the source's location in the color-magnitude space with respect to non-YSOs. We use this CMD score and the SED fitting results to define two classes of sources: high-reliability YSO candidates and possible YSO candidates. We found that, due to polycyclic aromatic hydrocarbon emission, about half of our sources have [3.6]-[4.5] and [4.5]-[5.8] colors not predicted by previous YSO models. The YSO candidates are spatially correlated with gas tracers.
- ID:
- ivo://CDS.VizieR/II/229
- Title:
- Sakurai's object (V4334 Sgr) in 1996-1998
- Short Name:
- II/229
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The photometric UBV observations of V4334 Sgr during 1996-1998 are presented. V4334 Sgr is the nucleus of a planetary nebula during the last helium flash of the shell source and it entered the R CrB phase.
- ID:
- ivo://CDS.VizieR/J/ApJ/804/7
- Title:
- SaMOSA: optical spectroscopy of 7 Fermi blazars
- Short Name:
- J/ApJ/804/7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multi-epoch optical spectroscopy of seven southern Fermi-monitored blazars from 2008 to 2013 using the Small and Medium Aperture Research Telescope System (SMARTS), with supplemental spectroscopy and polarization data from the Steward Observatory. We find that the emission lines are much less variable than the continuum; four of seven blazars had no detectable emission line variability over the 5 yr observation period. This is consistent with photoionization primarily by an accretion disk, allowing us to use the lines as a probe of disk activity. Comparing optical emission line flux with Fermi {gamma}-ray flux and optical polarized flux, we investigate whether relativistic jet variability is related to the accretion flow. In general, we see no such dependence, suggesting that the jet variability is likely caused by internal processes like turbulence or shock acceleration rather than a variable accretion rate. However, three sources showed statistically significant emission line flares in close temporal proximity to very large Fermi {gamma}-ray flares. While we do not have sufficient emission line data to quantitatively assess their correlation with the {gamma}-ray flux, it appears that in some cases the jet might provide additional photoionizing flux to the broad-line region (BLR), which implies that some {gamma}-rays are produced within the BLR, at least for these large flares.
- ID:
- ivo://CDS.VizieR/J/ApJ/886/93
- Title:
- SAMP. III. Opt. LCs and spectra of two AGNs
- Short Name:
- J/ApJ/886/93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Active galactic nuclei (AGNs) show a correlation between the size of the broad line region and the monochromatic continuum luminosity at 5100{AA}, allowing black hole mass estimation based on single-epoch spectra. However, the validity of the correlation is yet to be clearly tested for high-luminosity AGNs. We present the first reverberation mapping results of the Seoul National University AGN Monitoring Project (SAMP), which is designed to focus on luminous AGNs for probing the high end of the size-luminosity relation. We report time lag measurements of two AGNs, namely, 2MASSJ10261389+5237510 and SDSSJ161911.24+501109.2, using the light curves obtained over an ~1000d period with an average cadence of 10 and 20d, respectively, for photometry and spectroscopy monitoring. Based on a cross-correlation analysis and H{beta} line width measurements, we determine the H{beta} lag as 41.8_-6.0_^+4.9^ and 52.6_-14.7_^+17.6^ days in the observed frame, and black hole mass as 3.65_-0.57_^+0.49^x10^7^M_{sun}_ and 23.02_-6.56_^+7.81^x10^7^M_{sun}_, respectively, for 2MASS J1026 and SDSS J1619.
