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5491. R-band light curve of Qatar-1
ID:
ivo://CDS.VizieR/J/AJ/161/108
Title:
R-band light curve of Qatar-1
Short Name:
J/AJ/161/108
Date:
21 Oct 2021
Publisher:
CDS
Description:
Motivated by the unsettled conclusion on whether there are any transit timing variations (TTVs) for the exoplanet Qatar-1b, 10 new transit light curves are presented and a TTV analysis with a baseline of 1400 epochs is performed. Because the linear model provides a good fit with a reduced chi-square of {chi}_red_^2^=2.59 and the false-alarm probabilities of the possible TTV frequencies are as large as 35%, our results are consistent with a null-TTV model. Nevertheless, a new ephemeris with a reference time of T0=2455647.63360{+/-}0.00008 (BJD) and a period of P=1.4200236{+/-}0.0000001day is obtained. In addition, the updated orbital semimajor axis and planetary radius in units of stellar radius are provided, and the lower limit of the modified stellar tidal quality factor is also determined.
5492. R-band light curve of QSO J0158-4325 images
ID:
ivo://CDS.VizieR/J/ApJ/756/52
Title:
R-band light curve of QSO J0158-4325 images
Short Name:
J/ApJ/756/52
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present four new seasons of optical monitoring data and six epochs of X-ray photometry for the doubly imaged lensed quasar Q J0158-4325. The high-amplitude, short-period microlensing variability for which this system is known has historically precluded a time delay measurement by conventional methods. We attempt to circumvent this limitation by the application of a Monte Carlo microlensing analysis technique, but we are only able to prove that the delay must have the expected sign (image A leads image B). Despite our failure to robustly measure the time delay, we successfully model the microlensing at optical and X-ray wavelengths to find a half-light radius for soft X-ray emission log (r_1/2,X,soft_/cm)=14.3^+0.4^_-0.5_, an upper limit on the half-light radius for hard X-ray emission log (r_1/2,X,hard_/cm)<=14.6, and a refined estimate of the inclination-corrected scale radius of the optical R-band (rest frame 3100{AA}) continuum emission region of log (r_s_/cm)=15.6+/-0.3.
5493. R-band light curves of DES J0408-5359
ID:
ivo://CDS.VizieR/J/A+A/609/A71
Title:
R-band light curves of DES J0408-5359
Short Name:
J/A+A/609/A71
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present time-delay measurements for the new quadruply imaged quasar DES J0408-5354, the first quadruply imaged quasar found in the Dark Energy Survey (DES). Our result is made possible by implementing a new observational strategy using almost daily observations with the MPIA 2.2m telescope at La Silla observatory and deep exposures reaching a signal-to-noise ratio of about 1000 per quasar image. This data quality allows us to catch small photometric variations (a few mmag rms) of the quasar, acting on temporal scales much shorter than microlensing, hence making the time delay measurement very robust against microlensing. In only 7 months we measure very accurately one of the time delays in DES J0408-5354: Dt(AB)=-112.1+/-2.1-days (1.8%) using only the MPIA 2.2m data. In combination with data taken with the 1.2m Euler Swiss telescope, we also measure two delays involving the D component of the system Dt(AD)=-155.5+/-12.8-days (8.2%) and Dt(BD)=-42.4+/-17.6-days (41%), where all the error bars include systematics. Turning these time delays into cosmological constraints will require deep HST imaging or ground-based Adaptive Optics (AO), and information on the velocity field of the lensing galaxy.
5494. R-band light curves of GRB 060206 and GRB 060210
ID:
ivo://CDS.VizieR/J/ApJ/654/L21
Title:
R-band light curves of GRB 060206 and GRB 060210
Short Name:
J/ApJ/654/L21
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report on two z~4 gamma-ray bursts, GRB 060206 and GRB 060210, for which we have obtained well-sampled optical light curves. Both light curves show unusual behavior. GRB 060206 experienced a slow early decay, followed by a rapid increase in brightness by factor 2.5 about 1hr after the burst. Its afterglow then faded in a broken power-law fashion, with a smooth break at t_b_=0.6 days, but with additional, less dramatic bumps and wiggles. The afterglow of GRB 060210 is also unusual: the light curve was more or less flat between 60 and 300s after the burst, followed by a 70% increase at 600s after the burst, after which the light curve declined as a ~t^-1.3^ power law. We argue that anomalous optical afterglows are likely to be the norm and that such rapid optical variations should be seen in many bursts, given good enough sampling. Given that, some of the usual procedures, such as deriving the jet opening angle from fitting a smooth function to the optical light curve, might often have a poor statistical significance. We propose that the rapid rise at ~3000s in the optical for GRB 060206 and the optical bump at ~700s in GRB 060210 might be due to the turn-on of the external shock. The existence and timing of such features could provide us with valuable additional information about the bursts.
5495. R-band light curves of HE 0435-1223
ID:
ivo://CDS.VizieR/J/MNRAS/465/4914
Title:
R-band light curves of HE 0435-1223
Short Name:
J/MNRAS/465/4914
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results from thirteen years of optically monitoring the gravitationally lensed z_QSO_= 1.693 quasar HE 0435-1223. The R-band light curves of the four individual images of the quasar were obtained using deconvolution photometry for a total of 876 epochs. Several sharp quasar variability features strongly constrain the time delays between the quasar images. Using two different numerical techniques, we measured these delays for all possible pairs of quasar images while always processing the four light curves simultaneously. For both methods, the delays are compatible with the previous measurements presented in Courbin et al. (2011, Cat. J/A+A/536/A53) that used a subset of the present data and a different curve-shifting method. Our analysis of random and systematic errors accounts in a realistic way for the observed quasar variability, fluctuating microlensing magnification over a broad range of temporal scales, noise properties, and seasonal gaps. Finally, we find that our time-delay measurement methods yield compatible results when applied to subsets of the data.
5496. R-band light curves of HE 0435-1223
ID:
ivo://CDS.VizieR/J/A+A/536/A53
Title:
R-band light curves of HE 0435-1223
Short Name:
J/A+A/536/A53
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present accurate time delays for the quadruply imaged quasar HE 0435-1223. The delays were measured from 575 independent photometric points obtained in the R-band between January 2004 and March 2010. With seven years of data, we clearly show that quasar image A is affected by strong microlensing variations and that the time delays are best expressed relative to quasar image B.
5497. R-band light curves of 23 lensed QSOs
ID:
ivo://CDS.VizieR/J/A+A/640/A105
Title:
R-band light curves of 23 lensed QSOs
Short Name:
J/A+A/640/A105
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of 15 years of monitoring lensed quasars, which was conducted by the COSMOGRAIL programme at the Leonhard Euler 1.2m Swiss Telescope. The decade-long light curves of 23 lensed systems are presented for the first time. We complement our data set with other monitoring data available in the literature to measure the time delays in 18 systems, among which nine reach a relative precision better than 15% for at least one time delay. To achieve this, we developed an automated version of the curve-shifting toolbox PyCS to ensure robust estimation of the time delay in the presence of microlensing, while accounting for the errors due to the imperfect representation of microlensing. We also re-analysed the previously published time delays of RXj1131-1231 and HE0435-1223, by adding six and two new seasons of monitoring, respectively, and confirming the previous time-delay measurements. When the time delay measurement is possible, we corrected the light curves of the lensed images from their time delay and present the difference curves to highlight the microlensing signal contained in the data. To date, this is the largest sample of decade-long lens monitoring data, which is useful to measure $H_0$ and the size of quasar accretion discs with microlensing as well as to study quasar variability.
5498. R-band light curves of PG 1115+080
ID:
ivo://CDS.VizieR/J/A+A/616/A183
Title:
R-band light curves of PG 1115+080
Short Name:
J/A+A/616/A183
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present time-delay estimates for the quadruply imaged quasar PG 1115+080. Our results are based on almost daily observations for seven months at the ESO MPIA 2.2m telescope at La Silla Observatory, reaching a signal-to-noise ratio of about 1000 per quasar image. In addition, we re-analyze existing light curves from the literature that we complete with an additional three seasons of monitoring with the Mercator telescope at La Palma Observatory. When exploring the possible source of bias we considered the so-called microlensing time delay, a potential source of systematic error so far never directly accounted for in previous time-delay publications. In fifteen years of data on PG 1115+080, we find no strong evidence of microlensing time delay. Therefore not accounting for this effect, our time-delay estimates on the individual data sets are in good agreement with each other and with the literature.
5499. R-band light curves of RX J1131-1231
ID:
ivo://CDS.VizieR/J/A+A/556/A22
Title:
R-band light curves of RX J1131-1231
Short Name:
J/A+A/556/A22
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results from nine years of optically monitoring the gravitationally lensed z_QSO_=0.658 quasar RX J1131-1231. The R-band light curves of the four individual images of the quasar were obtained using deconvolution photometry for a total of 707 epochs. Several sharp quasar variability features strongly constrain the time delays between the quasar images. Using three different numerical techniques, we measured these delays for all possible pairs of quasar images while always processing the four light curves simultaneously. For all three methods, the delays between the three close images A, B, and C are compatible with being 0, while we measured the delay of image D to be 91 days, with a fractional uncertainty of 1.5% (1{sigma}), including systematic errors. Our analysis of random and systematic errors accounts in a realistic way for the observed quasar variability, fluctuating microlensing magnification over a broad range of temporal scales, noise properties, and seasonal gaps. Finally, we find that our time-delay measurement methods yield compatible results when applied to subsets of the data.
5500. R-band light curves of type II supernovae
ID:
ivo://CDS.VizieR/J/ApJ/820/33
Title:
R-band light curves of type II supernovae
Short Name:
J/ApJ/820/33
Date:
21 Oct 2021
Publisher:
CDS
Description:
During the first few days after explosion, Type II supernovae (SNe) are dominated by relatively simple physics. Theoretical predictions regarding early-time SN light curves in the ultraviolet (UV) and optical bands are thus quite robust. We present, for the first time, a sample of 57 R-band SN II light curves that are well-monitored during their rise, with >5 detections during the first 10 days after discovery, and a well-constrained time of explosion to within 1-3 days. We show that the energy per unit mass (E/M) can be deduced to roughly a factor of five by comparing early-time optical data to the 2011 model of Rabinak & Waxman, while the progenitor radius cannot be determined based on R-band data alone. We find that SN II explosion energies span a range of E/M=(0.2-20)x10^51^erg/(10M_{sun}), and have a mean energy per unit mass of <E/M>=0.85x10^51^erg/(10M_{sun}), corrected for Malmquist bias. Assuming a small spread in progenitor masses, this indicates a large intrinsic diversity in explosion energy. Moreover, E/M is positively correlated with the amount of ^56^Ni produced in the explosion, as predicted by some recent models of core-collapse SNe. We further present several empirical correlations. The peak magnitude is correlated with the decline rate ({Delta}m_15_), the decline rate is weakly correlated with the rise time, and the rise time is not significantly correlated with the peak magnitude. Faster declining SNe are more luminous and have longer rise times. This limits the possible power sources for such events.