- ID:
- ivo://CDS.VizieR/J/A+A/327/61
- Title:
- BV(RI)c photometry of S5 0716+714
- Short Name:
- J/A+A/327/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table 2 reports the journal of observations. For each date the measured magnitudes and their uncertainties in the four filters together with the used telescope are given. In some occasions several images were made in the course of the same night to search for intraday variability; these nights are indicated by an asterisk. The magnitude uncertainties have been evaluated by taking into account the mean dispersion of the internal error, but not the errors on the absolute calibration.
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- ID:
- ivo://CDS.VizieR/J/A+A/451/435
- Title:
- BV(RI)c photometry of S5 0716+714
- Short Name:
- J/A+A/451/435
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We address the topic of the intra-night optical variability of the BL Lac object S5 0716+714. To this purpose a long-term observational campaign was carried out, from 1996 to 2003, which allowed the collection of a very large data set, containing 10675 photometric measurements obtained in 102 nights. The source brightness varied in a range of about 2mag, although the majority of the observations were performed when it was in the range 13.0<R<13.75. Variability time scales were estimated from the rates of magnitude variation, which were found to have a distribution function well fitted by an exponential law with a mean value of 0.027mag/h, corresponding to an e-folding time scale of the flux {tau}_F_=37.6h. The highest rates of magnitude variation were around 0.10-0.12mag/h and lasted less than 2h. These rates were observed only when the source had an R magnitude <13.4, but this finding cannot be considered significant because of the low statistical occurrence. The distribution of {tau}_F_ has a well-defined modal value at 19h. Assuming the recent estimate of the beaming factor {delta} about 20, we derived a typical size of the emitting region of about (5x10^16^)/(1+z)cm. The possibility of searching for a possible correlation between the mean magnitude variation rate and the long-term changes in the velocity of the superluminal components in the jet is discussed.
- ID:
- ivo://CDS.VizieR/J/AZh/83/310
- Title:
- BV(RI)c photometry of S5 0716+714
- Short Name:
- J/AZh/83/310
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometric observations of the radio source S5 0716+71 were obtained in Johnson-Cousins BVRI filters from 1998 to 2001. with Zeiss-600 and Zeiss-1000 telescopes of SAO of the Russian Academy of Science.
- ID:
- ivo://CDS.VizieR/J/A+A/645/A137
- Title:
- BVRI light curves of PG 1553+113
- Short Name:
- J/A+A/645/A137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The TeV BL Lac object PG 1553+113 is one of the primary candidates for a binary supermassive black hole system. We study the flux and spectral variability of PG 1553+113 on intra-night to long-term timescales using (i) BVRI data collected over 76 nights from January 2016 to August 2019 involving nine optical telescopes and (ii) historical VR data (including ours) obtained for the period from 2005 to 2019. We analysed the light curves using various statistical tests, fitting and cross-correlation techniques, and methods for the search for periodicity. We examined the colour-magnitude diagrams before and after the corresponding light curves were corrected for the long-term variations. Our intra-night monitoring, supplemented with literature data, result in a low duty cycle of ~(10-17)%. In April 2019, we recorded a flare, which marks the brightest state of PG 1553+113 for the period from 2005 to 2019: R~13.2mag. This flare is found to show a clockwise spectral hysteresis loop on its VR colour-magnitude diagram and a time lag in the sense that the V-band variations lead the R-band ones. We obtain estimates of the radius, the magnetic field strength, and the electron energy that characterize the emission region related to the flare. We find a median period of (2.21+/-0.04) years using the historical light curves. In addition, we detect a secondary period of about 210 days using the historical light curves corrected for the long-term variations. We briefly discuss the possible origin of this period.
- ID:
- ivo://CDS.VizieR/J/AJ/136/1846
- Title:
- BVRI light curves of S5 0716+714
- Short Name:
- J/AJ/136/1846
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the optical photometry (B, V, R, and I) of the BL Lac object S5 0716+714 (z>0.3), which were observed with the 1m telescope at Yunnan Astronomical Observatory and the 1.56m telescope at Shanghai Astronomical Observatory from 2001 February to 2006 April.
- ID:
- ivo://CDS.VizieR/J/ApJ/849/161
- Title:
- BVRI light curves of the BL Lac object Mrk 501
- Short Name:
- J/ApJ/849/161
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present our observations of the optical intra-day variability (IDV) in {gamma}-ray BL Lac object Mrk 501. The observations were run with the 1.02m and 2.4m optical telescopes at Yunnan Observatories from 2005 April to 2012 May. The light curve at the R band on 2010 May 15 passes both variability tests (the F-test and the ANOVA test). A flare within the light curve on 2010 May 15 has a magnitude change of {Delta}m=0.03+/-0.005_stat_+/-0.007_sys_mag, a darkening timescale of {tau}_d_=26.7min., and an amplitude of IDV Amp=2.9%+/-0.7% . A decline described by 11 consecutive flux measurements within the flare can be fitted linearly with a Pearson's correlation coefficient r=0.945 at the confidence level of >99.99% . Under the assumptions that the IDV is tightly connected to the mass of the black hole, and that the flare duration, being two times {tau}_d_, is representative of the minimum characteristic timescale, we can derive upper bounds to the mass of the black hole. In the case of the Kerr black hole, the timescale of {Delta}t_min_^ob^=0.89hr gives M_{bullet}_<~10^9.20^M_{sun}_, which is consistent with measurements reported in the literature. This agreement indicates that the hypothesis about M_{bullet}_ and {Delta}t_min_^ob^ is consistent with the measurements/data.
- ID:
- ivo://CDS.VizieR/J/ApJS/218/18
- Title:
- 2004-2012 BVRI observations of blazar S5 0716+714
- Short Name:
- J/ApJS/218/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present long-term optical multi-band photometric monitoring of blazar S5 0716+714, from 2004 January 11 to 2012 November 4, with high temporal resolution of approximately 15 minutes in the BVRI bands. The source was in an active state during the whole monitoring campaign, showing intraday variability in 11 of 72 days. The average magnitudes in each band were B=14.398, V=13.821, R=13.255, and I=12.885. The overall variability amplitudes were {Delta}B=1^m^.834, , {Delta}V=2^m^.167, {Delta}R=2^m^.148, and {Delta}I=1^m^.912. The structure function showed that typical timescales for intraday variability were between approximately 2 and 7.5hr. The intraday variability amplitudes were from a few percent to approximately 30%. We found typical variation rates of approximately 0.05 mag/hr in both the rising and falling phases, with a minimal variability timescale of 130 minutes. A 10 day period short-term variability was observed simultaneously in the BVRI bands. The discrete correlation function suggests that there is significant correlated variability between the B- and I-band light curves. However, no significant time lags were detected. The spectral behaviors in the different variability episodes were studied, and our observations show bluer-when-brighter behavior on long, short, and intraday timescales for the blazar S5 0716+714. The variability and relevant spectral trends can be explained by the shock-in-jet scenario.
- ID:
- ivo://CDS.VizieR/J/AJ/155/31
- Title:
- 2005-2012 BVRI observations of blazar S5 0716+714
- Short Name:
- J/AJ/155/31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In order to search for the evidence of quasi-periodic oscillation (QPO) in blazars, multicolor optical observations of the BL Lacertae object S5 0716+714 were performed from 2005 to 2012. For I band observations on 2010 March 19 with low variability amplitude and low flux level, the same QPO~50 minutes at the 99% significance level is confirmed by the ZDCF method, Lomb-Scargle method, REDFIT, and fitting sinusoidal curves. The observed QPO is likely to be explained by accretion disk variability. If the observed QPO indicates an innermost stable orbital period from the accretion disk, the QPO~50 minutes corresponds to a black hole mass of 5.03x10^6^ M_{sun}_ for a non-rotating Schwarzschild black hole and 3.2x10^7^ M_{sun}_ for a maximally rotating Kerr black hole.
- ID:
- ivo://CDS.VizieR/J/A+AS/136/455
- Title:
- BVRI photometry of 3 BL Lac objects
- Short Name:
- J/A+AS/136/455
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of optical photometric (BVRI) monitoring of three BL Lac objects over a time interval of about four years are presented. The sources are three classical radio-selected BL Lac objects, BL Lac, OJ 287 and PKS 0735+178. During our observation OJ 287 was in the stage of a large periodic outburst which consisted of at least two peaks. Almost all the observations obtained over consecutive nights detected intranight variations. In 1995 and 1996 BL Lac kept in faint states, with fewer and smaller rapid flares and fluctuations. On the contrary, in late 1997 BL Lac was at the stage of a large outburst, accompanied with much more large amplitude rapid flares and fluctuations. PKS 0735+178 was almost at its faint end from 1994 to early 1998. Over this time interval, the intraday variations and microvariations in PKS 0735+178 were rare and the amplitude was very small, except a rapid darkening of ~0.4mag on 24 January 1995. Previous work by Webb et al. (1988AJ.....95..374W), Wagner et al. (1996AJ....111.2187W) and Pian et al. (1997ApJ...486..784P) also showed the same behaviour of variability as BL Lac and PKS 0735+178 in BL Lac, S5 0716+714, PKS 2155-304, respectively. We propose that the motion of orientation of the relativistic jet in a BL Lac object be responsible for these variability behaviours.
- ID:
- ivo://CDS.VizieR/J/A+AS/132/83
- Title:
- BVRI photometry of 7 BL Lac objects
- Short Name:
- J/A+AS/132/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Seven BL Lac objects have been photometrically observed in an effort to study the difference of optical intraday variability between the radio-selected BL Lac objects (RBLs) and X-ray-selected BL Lac objects (XBLs). The objects we observed are selected arbitrarily. They are four RBLs, PKS 0735+178, PKS 0754+101, OJ 287 and BL Lac, and three XBLs, H 0323+022, H 0548-322 and H 2154-304. During the observation all of them exhibited microvariation, and H 0323+022 and H 0548-322 sometimes showed brightness oscillation. PKS 0735+178 and BL Lac were in their faint states and not very active. It seems that RBLs do not show microvariability more frequently than XBLs.