- ID:
- ivo://CDS.VizieR/J/ApJ/642/L99
- Title:
- R-band photometry of GRB 060206
- Short Name:
- J/ApJ/642/L99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Rapid Telescopes for Optical Response (RAPTOR) system at Los Alamos National Laboratory observed GRB 060206 starting 48.1min after gamma-ray emission triggered the Burst Alert Telescope on board the Swift satellite. The afterglow light curve measured by RAPTOR shows a spectacular rebrightening by ~1mag about 1hr after the trigger and peaks at R~16.4mag. Shortly after the onset of the explosive rebrightening, the optical transient doubled its flux on a timescale of about 4min. The total R-band fluence received from GRB 060206 during this episode is 2.3x10^9^ergs/cm^2^. In the rest frame of the burst (z=4.045), this yields an isotropic equivalent energy release of E_iso_~0.7x10^50^ergs in just a narrow UV band, {lambda}~130{+/-}22nm. We discuss the implications of RAPTOR observations for untriggered searches for fast optical transients and studies of GRB environments at high redshift.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/391/481
- Title:
- R-band photometry of SBS1520+530
- Short Name:
- J/A+A/391/481
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical R-band light curves of the gravitationally lensed quasar SBS 1520+530 derived from data obtained at the Nordic Optical Telescope, from February 1999 to May 2001. A time delay of 130+/-3days (1{sigma}) is determined from the light curves. In addition, spectra of SBS 1520+530 obtained at the Keck Observatory are spatially deconvolved in order to extract the spectrum of the faint lensing galaxy, free of any contamination by the light from the bright quasar images. This spectrum indicates a lens redshift z=0.717, in agreement with one of the absorption systems found in the quasar spectra. The best mass model of the system includes a second nearby galaxy and a cluster of galaxies in addition to the main lensing galaxy. Adopting this model and an {Omega}=0.3, {Lambda}=0.7 cosmology, our time-delay measurement yields a Hubble constant of H_0_=51+/-9km/s/Mpc (1{sigma} error).
- ID:
- ivo://CDS.VizieR/J/A+A/544/A51
- Title:
- R-band photometry of the lensed quasar UM673
- Short Name:
- J/A+A/544/A51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observational data of the double lensed quasar UM673 obtained with the 1.5-m telescope of the Maidanak Observatory and the 1.3-m SMARTS telescope at CTIO between 2006 and 2010. We combine these data with our previously published observational data of UM673 to measure the time delay between the UM673 images. We also analyze the time evolution of the flux ratio between the UM673 images.
- ID:
- ivo://CDS.VizieR/J/ApJ/807/5
- Title:
- R-band polarimetry data in the region of Lupus I
- Short Name:
- J/ApJ/807/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Deep R-band CCD linear polarimetry collected for fields with lines of sight toward the Lupus I molecular cloud is used to investigate the properties of the magnetic field within this molecular cloud. The observed sample contains about 7000 stars, almost 2000 of them with a polarization signal-to-noise ratio larger than 5. These data cover almost the entire main molecular cloud and also sample two diffuse infrared patches in the neighborhood of Lupus I. The large-scale pattern of the plane-of-sky projection of the magnetic field is perpendicular to the main axis of Lupus I, but parallel to the two diffuse infrared patches. A detailed analysis of our polarization data combined with the Herschel/SPIRE 350{mu}m dust emission map shows that the principal filament of Lupus I is constituted by three main clumps that are acted on by magnetic fields that have different large-scale structural properties. These differences may be the reason for the observed distribution of pre- and protostellar objects along the molecular cloud and the cloud's apparent evolutionary stage. On the other hand, assuming that the magnetic field is composed of large-scale and turbulent components, we find that the latter is rather similar in all three clumps. The estimated plane-of-sky component of the large-scale magnetic field ranges from about 70 to 200{mu}G in these clumps. The intensity increases toward the Galactic plane. The mass-to-magnetic flux ratio is much smaller than unity, implying that Lupus I is magnetically supported on large scales.
- ID:
- ivo://CDS.VizieR/J/ApJ/811/117
- Title:
- R-band PTF observations of SNe IIb
- Short Name:
- J/ApJ/811/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The progenitor stars of several Type IIb supernovae (SNe) show indications of extended hydrogen envelopes. These envelopes might be the outcome of luminous energetic pre-explosion events, so-called precursor eruptions. We use the Palomar Transient Factory (PTF) pre-explosion observations of a sample of 27 nearby SNe IIb to look for such precursors during the final years prior to the SN explosion. No precursors are found when combining the observations in 15-day bins, and we calculate the absolute-magnitude-dependent upper limit on the precursor rate. At the 90% confidence level, SNe IIb have on average <0.86 precursors as bright as an absolute R-band magnitude of -14 in the final 3.5 years before the explosion and <0.56 events over the final year. In contrast, precursors among SNe IIn have a >~5 times higher rate. The kinetic energy required to unbind a low-mass stellar envelope is comparable to the radiated energy of a few-weeks-long precursor that would be detectable for the closest SNe in our sample. Therefore, mass ejections, if they are common in such SNe, are radiatively inefficient or have durations longer than months. Indeed, when using 60-day bins, a faint precursor candidate is detected prior to SN 2012cs (~2% false-alarm probability). We also report the detection of the progenitor of SN 2011dh that does not show detectable variability over the final two years before the explosion. The suggested progenitor of SN 2012P is still present, and hence is likely a compact star cluster or an unrelated object.
- ID:
- ivo://CDS.VizieR/J/ApJ/731/118
- Title:
- R-band variability in blazar S5 0716+71
- Short Name:
- J/ApJ/731/118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report rapid optical variability for the blazar S5 0716+71 during 2010 March 8-10 and 19-20 in the CCD observations made from Mt. Abu Infrared Observatory. The light curves are constructed for a duration longer than 3hr each night, with very high temporal resolution (~45s in the R band). During 2010 March 8, the source smoothly decayed by about 0.15mag in 2.88hr, apart from a fast flicker lasting about 30 minutes. S5 0716+71 brightened during March 9 and 10, showing high activity, while it was relatively faint (>14mag in the R band) albeit variable during March 19-20. During March 9 and 10, rapid flickers in the intensity modulated the long-term intra-night (~3hr) variations. The present observations suggest that the blazar S5 0716+71 showed night-to-night and intra-night variability at various timescales with a 100% duty cycle for variation along with microvariability at significant levels. On a night-to-night basis, the source exhibits mild bluer-when-brighter nature. The interaction of shocks with local inhomogeneities in the jet appears to cause intra-night variations, while microvariations could be due to small-scale perturbations intrinsic to the jet.
- ID:
- ivo://CDS.VizieR/J/AJ/135/1384
- Title:
- R-band variability in 5 blazars
- Short Name:
- J/AJ/135/1384
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We selected a sample of a dozen blazars which are the prime candidates for simultaneous multi-wavelength observing campaigns in their outburst phase. We searched for optical outbursts, intra-day variability (IDV) and short-term variability in these blazars. We carried out optical photometric monitoring of nine of these blazars in 13 observing nights during our observing run of 2006 October 27-2007 March 20 using the 1.0m optical telescope equipped with CCD detector and BVRI Johnson broadband filters at Yunnan Astronomical Observatory, Kunming, China. We observed densely sampled 1534 image frames of these nine blazars.
- ID:
- ivo://CDS.VizieR/J/A+A/459/679
- Title:
- RB photometry of LSBG in Coma
- Short Name:
- J/A+A/459/679
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on a search for faint (R total magnitude fainter than 21) and low surface brightness galaxies (R central surface brightness fainter than ~24) (fLSBs) in a 0.72x0.82deg^2^ area centered on the Coma cluster. We analyzed deep B and R band CCD imaging obtained using the CFH12K camera at CFHT and found 735 fLSBs. The total B magnitudes, at the Coma cluster redshift, range from -13 to -9 with B central surface brightness as faint as 27mag/arcsec^2^.
- ID:
- ivo://CDS.VizieR/J/ApJ/837/45
- Title:
- 2006-2012 Rc-band & 4.8GHz obs. of AO 0235+164
- Short Name:
- J/ApJ/837/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Variability is one of the extreme observational properties of BL Lacertae objects. AO 0235+164 is a well-studied BL Lac throughout all electromagnetic wavebands. In the present work, we show its optical R-band photometric observations carried out during the period from 2006 November to 2012 December using the Ap6E CCD camera attached to the primary focus of the 70cm meniscus telescope at Abastumani Observatory, Georgia. During our monitoring period, it showed a large variation of {Delta}R=4.88mag (14.19-19.07mag) and a short timescale of {Delta}T_v_=73.5minutes. During the period of 2006 December to 2009 November, we made radio observations of the source using the 25m radio telescope at Xinjiang Astronomical Observatory. By adopting a discrete correlation function to the optical and radio observations we found that the optical variation leads a radio variation of 23.2+/-12.9days.
- ID:
- ivo://CDS.VizieR/J/A+A/642/A193
- Title:
- Rc-band light curves of 6 lensed QSOs
- Short Name:
- J/A+A/642/A193
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present six new time-delay measurements obtained from Rc-band monitoring data acquired at the MPIA 2.2m telescope at La Silla observatory between October 2016 and February 2020. The lensed quasars HE 0047-1756, WG 0214-2105, DES 0407-5006, 2M 1134-2103, PSJ 1606-2333 and DES 2325-5229 were observed almost daily at high signal-to-noise ratio to obtain high-quality light curves where we can record fast and small-amplitude variations of the quasars. We measure time delays between all pairs of multiple images with only one or two seasons of monitoring at the exception of the time delays relative to image D of PSJ 1606-2333. The most precise estimate is obtained for the delay between image A and image B of DES 0407-5006, with {tau}_AB_=-128.4^+3.5^_-3.8_ days (2.8% precision) including systematics due to extrinsic variability in the light curves. For HE 0047-1756, we combine our high-cadence data with measurements from decade-long light-curves from previous COSMOGRAIL campaigns, and reach a precision of 0.9 day on the final measurement. The present work demonstrates the feasibility of measuring time delays in lensed quasars in only one or two seasons, provided high signal-to-noise ratio data are obtained at a cadence close to daily.
