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4701. Opt. follow-up of GW170817 counterpart
ID:
ivo://CDS.VizieR/J/ApJ/848/L29
Title:
Opt. follow-up of GW170817 counterpart
Short Name:
J/ApJ/848/L29
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of prompt optical follow-up of the electromagnetic counterpart of the gravitational-wave event GW170817 by the Transient Optical Robotic Observatory of the South Collaboration. We detected highly significant dimming in the light curves of the counterpart ({Delta}g=0.17+/-0.03mag, {Delta}r=0.14+/-0.02mag, {Delta}i=0.10+/-0.03mag) over the course of only 80 minutes of observations obtained ~35hr after the trigger with the T80-South telescope. A second epoch of observations, obtained ~59hr after the event with the EABA 1.5m telescope, confirms the fast fading nature of the transient. The observed colors of the counterpart suggest that this event was a "blue kilonova" relatively free of lanthanides.
4702. Optical and HI properties of galaxies in voids
ID:
ivo://CDS.VizieR/J/AJ/144/16
Title:
Optical and HI properties of galaxies in voids
Short Name:
J/AJ/144/16
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have carefully selected a sample of 60 galaxies that reside in the deepest underdensities of geometrically identified voids within the Sloan Digital Sky Survey. HI imaging of 55 galaxies with the Westerbork Synthesis Radio Telescope reveals morphological and kinematic signatures of ongoing interactions and gas accretion. We probe a total volume of 485Mpc^3^ within the voids, with an angular resolution of 8kpc at an average distance of 85Mpc. We reach column density sensitivities of 5x10^19^/cm^-2^, corresponding to an HI mass limit of 3x10^8^M_{sun}_. We detect HI in 41 galaxies, with total masses ranging from 1.7x10^8^ to 5.5x10^9^M_{sun}_. The upper limits on the 14 non-detections are not inconsistent with their luminosities, given their expected HI mass-to-light ratios. We find that the void galaxies are generally gas-rich, low-luminosity, blue disk galaxies, with optical and HI properties that are not unusual for their luminosity and morphology. The sample spans a range of absolute magnitudes (-16.1>M_r_>-20.4) and colors (0.06<g-r<0.87), and includes disk and irregular galaxies. We also identify three as early-type galaxies, all of which are not detected in HI. All galaxies have stellar masses less than 3x10^10^M_{sun}_, and many have kinematic and morphological signs of ongoing gas accretion, suggesting that the void galaxy population is still in the process of assembling. The small-scale clustering in the void, within 600kpc and 200km/s, is similar to that in higher density regions, and we identify 18 HI-rich neighboring galaxies in the voids. Most are within 100kpc and 100km/s of the targeted galaxy, and we find no significant population of HI-rich low-luminosity galaxies filling the voids, contrary to what is predicted by simulations.
4703. Optical and IR photometry in the HII region Sh2-242
ID:
ivo://CDS.VizieR/J/AJ/159/153
Title:
Optical and IR photometry in the HII region Sh2-242
Short Name:
J/AJ/159/153
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present here identification and characterization of the young stellar population associated with an active star-forming site Sh2-242. We used our own new optical imaging and spectroscopic observational data, as well as several archival catalogs, e.g., Pan-STARRS-1, Gaia-DR2, Isaac Newton Telescope Photometric H-Alpha Survey (IPHAS), Wide-field InfraRed Camera, 2MASS, and Spitzer. Slit spectroscopic results confirm the classification of the main ionizing source BD+26980 as an early-type star of spectral type B0.5V. The spectrophotometric distance of the star is estimated as 2.08{+/-}0.24kpc, which confirms the source as a member of the cluster. An extinction map covering a large area (diameter ~50') is generated with H and K photometry toward the region. From the map, three distinct locations of peak extinction complexes (A_V_~7-17mag) are identified for the very first time. Using the infrared color excess, a total of 33 Class I and 137 Class II young objects are classified within the region. The IPHAS photometry reveals classification of 36 H{alpha} emitting sources, which might be class II objects. Among 36 H{alpha} emitting sources, 5 are already identified using infrared excess emission. In total, 201 young objects are classified toward S242 from this study. The membership status of the young sources is further windowed with the inclusion of parallax from the Gaia DR2 catalog. Using the optical and infrared color-magnitude diagrams, the young stellar objects are characterized with an average age of ~1Myr and masses in the range 0.1-3.0M_{sun}_.
4704. Optical and IR photometry of [KOS94] HA11
ID:
ivo://CDS.VizieR/J/ApJ/733/L8
Title:
Optical and IR photometry of [KOS94] HA11
Short Name:
J/ApJ/733/L8
Date:
21 Oct 2021
Publisher:
CDS
Description:
We conducted a long-term optical photometric and spectroscopic monitoring of the strongly variable, accreting young sun-like star [KOS94] HA11, associated with the dark cloud Lynds 1340 that exhibited large amplitude (5-6mag in the I_C_ band) brightness variations on 2-3 years timescales, flat spectral energy distribution (SED), and extremely strong (300<~EW/{AA}<~900) H{alpha} emission. In this Letter we describe the basic properties of the star, derived from our observations between 1999 and 2011, and put into context the observed phenomena. The observed variations in the emission spectra, near-infrared colors, and SED suggest that [KOS94] HA11 (spectral type: K7-M0) is an eruptive young star, possibly similar in nature to V1647 Ori: its large-scale photometric variations are governed by variable accretion rate, associated with variations in the inner disk structure. The star recently has undergone strong and rapid brightness variations, thus its further observations may offer a rare opportunity for studying structural and chemical rearrangements of the inner disk, induced by variable central luminosity.
4705. Optical and IR photometry of OGLE-2017-BLG-0406
ID:
ivo://CDS.VizieR/J/AJ/160/74
Title:
Optical and IR photometry of OGLE-2017-BLG-0406
Short Name:
J/AJ/160/74
Date:
10 Dec 2021
Publisher:
CDS
Description:
We report the discovery and analysis of the planetary microlensing event OGLE-2017-BLG-0406, which was observed both from the ground and by the Spitzer satellite in a solar orbit. At high magnification, the anomaly in the light curve was densely observed by ground-based-survey and follow-up groups, and it was found to be explained by a planetary lens with a planet/host mass ratio of q=7.0x10^-4^ from the light-curve modeling. The ground-only and Spitzer-"only" data each provide very strong one-dimensional (1D) constraints on the 2D microlens parallax vector {pi}_E_. When combined, these yield a precise measurement of {pi}_E_ and of the masses of the host M_host_=0.56{+/-}0.07M_{sun} and planet M_planet_=0.41{+/-}0.05M_Jup_. The system lies at a distance D_L_=5.2{+/-}0.5 kpc from the Sun toward the Galactic bulge, and the host is more likely to be a disk population star according to the kinematics of the lens. The projected separation of the planet from the host is a_{perp}_=3.5{+/-}0.3au (i.e., just over twice the snow line). The Galactic-disk kinematics are established in part from a precise measurement of the source proper motion based on OGLE-IV data. By contrast, the Gaia proper-motion measurement of the source suffers from a catastrophic 10{sigma} error.
4706. Optical and mid-IR photometry of PTF 10nvg
ID:
ivo://CDS.VizieR/J/AJ/145/59
Title:
Optical and mid-IR photometry of PTF 10nvg
Short Name:
J/AJ/145/59
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report extensive new photometry and spectroscopy of the highly variable young stellar object PTF 10nvg (also known as IRAS 20496+4354 and V2492 Cyg), including optical and near-infrared time-series data as well as mid-infrared and millimeter data. Following the previously reported 2010 rise to R_PTF_<~13.5^m^ and subsequent fade, during 2011 and 2012 the source underwent additional episodes of brightening, followed by several magnitude dimming events including prolonged faint states at R_PTF_>~20^m^. The observed high-amplitude variations are largely consistent with extinction changes ({Delta}A_V_ up to 30mag) having a ~220day quasi-periodic signal. However, photometry measured when the source was near maximum brightness in mid-2010 as well as in late-2012 does not phase well to this period. Spectral evolution includes not only changes in the spectral slope but also correlated variation in the prominence of TiO/VO/CO bands and atomic line emission, as well as anti-correlated variation in forbidden line emission which, along with H_2_, dominates optical and infrared spectra at faint epochs. Notably, night-to-night variations in several forbidden doublet strengths and ratios are observed. High-dispersion spectra were obtained in a variety of photometric states and reveal time-variable line profiles. Neutral and singly ionized atomic species are likely formed in an accretion flow and/or impact while the origin of zero-velocity atomic LiI{lambda}6707 in emission is unknown. Forbidden lines, including several rare species, exhibit blueshifted emission profiles and likely arise from an outflow/jet. Several of these lines are also seen spatially offset from the continuum source position, presumably in a shocked region of an extended jet. Blueshifted absorption components of the NaI D doublet, KI{lambda}{lambda}7665,7669 doublet, and the OI 7774 triplet, as well as blueshifted absorption components seen against the broad H{alpha} and CaII triplet emission lines, similarly are formed in the outflow. CARMA maps resolve on larger scales a spatially extended outflow in millimeter-wavelength CO. We attribute the recently observed photometric and spectroscopic behavior to rotating circumstellar disk material located at separation a~0.7(M_*_/M_{sun}_)^1/3^AU from the continuum source, causing the semi-periodic dimming. Occultation of the central star as well as the bright inner disk and the accretion/outflow zones renders shocked gas in the inner part of the jet amenable to observation at the faint epochs. We discuss PTF 10nvg as a source exhibiting both accretion-driven (perhaps analogous to V1647 Ori) and extinction-driven (perhaps analogous to UX Ori or GM Cep) high-amplitude variability phenomena.
4707. Optical and near-infrared photometry in Orion A
ID:
ivo://CDS.VizieR/J/A+A/564/A29
Title:
Optical and near-infrared photometry in Orion A
Short Name:
J/A+A/564/A29
Date:
21 Oct 2021
Publisher:
CDS
Description:
Following the recent discovery a large population of young stars in front of the Orion Nebula we carried out an observational campaign with the DECam wide-field camera covering approximately 10 square degrees centered on NGC 1980 to confirm, probe the extent, and characterize this foreground population of pre-main sequence stars. We used multi-wavelength wide field images and catalogs to identify potential foreground pre-main sequence stars using a novel probabilistic technique based on a careful selection of colors and luminosities. We confirmed the presence of a large foreground population towards the Orion A cloud. This population contains several distinct sub-groups including NGC 1980 and NGC 1981 and stretches over several degrees in front of the Orion A cloud. By comparing the location of their sequence in various color-magnitude diagrams to other clusters, we found a distance and an age of 380pc and 5 to 10Myr, in good agreement with previous estimates. Our final sample includes 2123 candidate members and is complete from below the hydrogen burning limit to about 0.3M_{sun}_ where the data starts to be limited by saturation. Extrapolating the mass function to the high masses, we estimated a total number of ~2600 members in the surveyed region.
4708. Optical and near-IR light curves of 64 SNe
ID:
ivo://CDS.VizieR/J/ApJS/213/19
Title:
Optical and near-IR light curves of 64 SNe
Short Name:
J/ApJS/213/19
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a densely sampled, homogeneous set of light curves of 64 low-redshift (z<~0.05) stripped-envelope supernovae (SNe of Type IIb, Ib, Ic, and Ic-BL). These data were obtained between 2001 and 2009 at the Fred L. Whipple Observatory (FLWO) on Mount Hopkins in Arizona, with the optical FLWO 1.2m and the near-infrared (NIR) Peters Automated Infrared 1.3m telescopes. Our data set consists of 4543 optical photometric measurements on 61 SNe, including a combination of UBVRI, UBVr'i', and u'BVr'i', and 1919 JHK_s_ NIR measurements on 25 SNe. This sample constitutes the most extensive multi-color data set of stripped-envelope SNe to date. Our photometry is based on template-subtracted images to eliminate any potential host-galaxy light contamination. This work presents these photometric data, compares them with data in the literature, and estimates basic statistical quantities: date of maximum, color, and photometric properties. We identify promising color trends that may permit the identification of stripped-envelope SN subtypes from their photometry alone. Many of these SNe were observed spectroscopically by the Harvard-Smithsonian Center for Astrophysics (CfA) SN group, and the spectra are presented in a companion paper. A thorough exploration that combines the CfA photometry and spectroscopy of stripped-envelope core-collapse SNe will be presented in a follow-up paper.
4709. Optical and NIR LCs of the nearby SN 2017cbv
ID:
ivo://CDS.VizieR/J/ApJ/863/90
Title:
Optical and NIR LCs of the nearby SN 2017cbv
Short Name:
J/ApJ/863/90
Date:
21 Oct 2021
Publisher:
CDS
Description:
On 2017 March 11, the DLT40 Transient Discovery Survey discovered SN2017cbv in NGC 5643, a Type 2 Seyfert Galaxy in the Lupus Constellation. SN 2017cbv went on to become a bright Type Ia supernova, with a Vmax of 11.51+/-0.05mag. We present early time optical and infrared photometry of SN 2017cbv covering the rise and fall of over 68 days. We find that SN 2017cbv has a broad light curve {Delta}m_15_(B)=0.88+/-0.07, a B-band maximum at 2457840.97+/-0.43, a negligible host galaxy reddening where E(B-V)_host_~0, and a distance modulus of 30.49+/-0.32 to the SN, corresponding to a distance of 12.58_-1.71_^+1.98^Mpc. We also present the results of two different numerical models we used for analysis in this paper: SALT2, an empirical model for Type Ia supernova optical light curves that accounts for variability components; and SNooPy, the CSP-II light-curve model that covers both optical and near-infrared wavelengths and is used for distance estimates.
4710. Optical and NIR observation of SN (Ia) 2017cbv
ID:
ivo://CDS.VizieR/J/ApJ/904/14
Title:
Optical and NIR observation of SN (Ia) 2017cbv
Short Name:
J/ApJ/904/14
Date:
24 Mar 2022 06:19:55
Publisher:
CDS
Description:
Supernova (SN) 2017cbv in NGC5643 is one of a handful of Type Ia supernovae (SNeIa) reported to have excess blue emission at early times. This paper presents extensive BVRIYJHKs-band light curves of SN2017cbv, covering the phase from -16 to +125days relative to B-band maximum light. The SN2017cbv reached a B-band maximum of 11.710{+/-}0.006mag, with a postmaximum magnitude decline of {Delta}m15(B)=0.990{+/-}0.013mag. The SN suffered no host reddening based on Phillips intrinsic color, the Lira-Phillips relation, and the CMAGIC diagram. By employing the CMAGIC distance modulus {mu}=30.58{+/-}0.05mag and assuming H0=72km/s/Mpc, we found that 0.73M{sun} 56Ni was synthesized during the explosion of SN2017cbv, which is consistent with estimates using reddening- and distance-free methods via the phases of the secondary maximum of the near-IR- (NIR-) band light curves. We also present 14 NIR spectra from -18 to +49 days relative to the B-band maximum light, providing constraints on the amount of swept-up hydrogen from the companion star in the context of the single degenerate progenitor scenario. No Pa{beta} emission feature was detected from our postmaximum NIR spectra, placing a hydrogen mass upper limit of 0.1M{sun}. The overall optical/NIR photometric and NIR spectral evolution of SN2017cbv is similar to that of a normal SN Ia, even though its early evolution is marked by a flux excess not seen in most other well-observed normal SNe Ia. We also compare the exquisite light curves of SN2017cbv with some Mch delayed detonation models and sub-Mch double detonation models.