- ID:
- ivo://CDS.VizieR/J/ApJ/768/40
- Title:
- R-band and polarimetry of the blazar S5 0716+71
- Short Name:
- J/ApJ/768/40
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of optical (R band) photometric and polarimetric monitoring and Very Long Baseline Array (VLBA) imaging of the blazar S5 0716+714 along with Fermi {gamma}-ray data during a multi-waveband outburst in 2011 October. We analyze total and polarized intensity images of the blazar obtained with the VLBA at 43GHz during and after the outburst. Monotonic rotation of the linear polarization vector at a rate of >~50{deg} per night coincided with a sharp maximum in {gamma}-ray and optical flux. At the same time, within the uncertainties, a new superluminal knot appeared with an apparent speed of 21+/-2c. The general multi-frequency behavior of the outburst can be explained within the framework of a shock wave propagating along a helical path in the blazar's jet.
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- 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.
- 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.
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJ/747/L5
- Title:
- R-band observations of PTF 10vgv
- Short Name:
- J/ApJ/747/L5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of PTF 10vgv, a Type Ic supernova (SN) detected by the Palomar Transient Factory, using the Palomar 48 inch telescope (P48). R-band observations of the PTF 10vgv field with P48 probe the SN emission from its very early phases (about two weeks before R-band maximum) and set limits on its flux in the week prior to the discovery. Our sensitive upper limits and early detections constrain the post-shock-breakout luminosity of this event. Via comparison to numerical (analytical) models, we derive an upper-limit of R<~4.5R_{sun}_ (R<~1R_{sun}_) on the radius of the progenitor star, a direct indication in favor of a compact Wolf-Rayet star. Applying a similar analysis to the historical observations of SN 1994I yields R<~1/4R_{sun}_ for the progenitor radius of this SN.
- ID:
- ivo://CDS.VizieR/J/AJ/157/186
- Title:
- r'-band photometry of comet 96P/Machholz 1
- Short Name:
- J/AJ/157/186
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We observed comet 96P/Machholz 1 on a total of nine nights before and after perihelion during its 2017/2018 apparition. Both its unusually small perihelion distance and the observed fragmentation during multiple apparitions make 96P an object of great interest. Our observations show no evidence of a detectable dust coma, implying that we are observing a bare nucleus at distances ranging from 2.3 to 3.8 au. Based on this assumption, we calculated its color and found average values of g'-r'=0.50+/-0.04, r'-i'=0.17+/-0.03, and i'-z'=0.06+/-0.04. These are notably more blue than those of the nuclei of other Jupiter-family and long-period comets. Furthermore, assuming a bare nucleus, we found an equivalent nuclear radius of 3.4+/-0.2 km with an axial ratio of at least 1.6+/-0.1. The lightcurve clearly displays one large peak, one broad flat peak, and two distinct troughs, with a clear asymmetry that suggests that the shape of the nucleus deviates from that of a simple triaxial ellipsoid. This asymmetry in the lightcurve allowed us to constrain the nuclear rotation period to 4.10+/-0.03 hr and 4.096+/-0.002 hr before and after perihelion, respectively. Within the uncertainties, 96P's rotation period does not appear to have changed throughout the apparition, and we conclude a maximum possible change in rotation period of 130 s. The observed properties were compared to those of comet 322P and interstellar object 1I/'Oumuamua in an attempt to study the effects of close perihelion passages on cometary surfaces and their internal structure and the potential interstellar origin of 96P.
- 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/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.
