- ID:
- ivo://CDS.VizieR/J/ApJ/871/233
- Title:
- Photometric redshifts in the EGOODS-North field
- Short Name:
- J/ApJ/871/233
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep J- and H-band images in the extended Great Observatories Origins Deep Survey-North field covering an area of 0.22deg^2^. The observations were taken using WIRCam on the 3.6m Canada-France-Hawaii Telescope. Together with the reprocessed Ks-band image, the 5{sigma} limiting AB magnitudes (in 2" diameter apertures) are 24.7, 24.2, and 24.4 AB mag in the J, H, and Ks bands, respectively. We also release a multiband photometry and photometric redshift catalog containing 93598 sources. For non-X-ray sources, we obtained a photometric redshift accuracy {sigma}_NMAD_=0.036 with an outlier fraction {eta}=7.3%. For X-ray sources, which are mainly active galactic nuclei (AGNs), we cross-matched our catalog with the updated 2M-CDFN X-ray catalog from Xue+ (2016, J/ApJS/224/15) and found that 658 out of 683 X-ray sources have counterparts. GALEX UV data are included in the photometric redshift computation for the X-ray sources to give {sigma}_NMAD_=0.040 with {eta}=10.5%. Our approach yields more accurate photometric redshift estimates compared to previous works in this field. In particular, by adopting AGN-galaxy hybrid templates, our approach delivers photometric redshifts for the X-ray counterparts with fewer outliers compared to the 3D-Hubble Space Telescope catalog, which fit these sources with galaxy-only templates.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/491/655
- Title:
- Photometry and spectroscopy of RN LMC 1968
- Short Name:
- J/MNRAS/491/655
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive review of all observations of the eclipsing recurrent Nova LMC 1968 in the Large Magellanic Cloud which was previously observed in eruption in 1968, 1990, 2002, 2010, and most recently in 2016. We derive a probable recurrence time of 6.2+/-1.2yr and provide the ephemerides of the eclipse. In the ultraviolet-optical-IR photometry the light curve shows high variability right from the first observation around 2 d after eruption. Therefore no colour changes can be substantiated. Outburst spectra from 2016 and 1990 are very similar and are dominated by H and He lines longward of 2000{AA}. Interstellar reddening is found to be E(B-V)=0.07+/-0.01. The super soft X-ray luminosity is lower than the Eddington luminosity and the X-ray spectra suggest the mass of the white dwarf (WD) is larger than 1.3M_{sun}_. Eclipses in the light curve suggest that the system is at high orbital inclination. On day 4 after the eruption a recombination wave was observed in FeII ultraviolet absorption lines. Narrow-line components are seen after day 6 and explained as being due to reionization of ejecta from a previous eruption. The UV spectrum varies with orbital phase, in particular a component of the HeII 1640{AA} emission line, which leads us to propose that early-on the inner WD Roche lobe might be filled with a bound opaque medium prior to the re-formation of an accretion disc. Both this medium and the ejecta can cause the delay in the appearance of the soft X-ray source.
- ID:
- ivo://CDS.VizieR/J/ApJS/198/1
- Title:
- Photometry catalogs for the Lockman Hole
- Short Name:
- J/ApJS/198/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present broadband photometry and photometric redshifts for 187611 sources located in ~0.5deg^2^ in the Lockman Hole area. The catalog includes 388 X-ray-detected sources identified with the very deep XMM-Newton observations available for an area of 0.2deg^2^. The source detection was performed on the Rc-, z'-, and B-band images and the available photometry is spanning from the far-ultraviolet to the mid-infrared, reaching in the best-case scenario 21 bands. Astrometry corrections and photometric cross-calibrations over the entire data set allowed the computation of accurate photometric redshifts. Special treatment is undertaken for the X-ray sources, the majority of which are active galactic nuclei (AGNs). For normal galaxies, comparing the photometric redshifts to the 253 available spectroscopic redshifts, we achieve an accuracy of {sigma}_{Delta}z/(1+z)_=0.036, with 12.6% outliers. For the X-ray-detected sources, compared to 115 spectroscopic redshifts, the accuracy is {sigma}_{Delta}z/(1+z)_=0.069, with 18.3% outliers, where the outliers are defined as sources with |z_phot_-z_spec_|>0.15x(1+z_spec_).
- ID:
- ivo://CDS.VizieR/J/MNRAS/455/2918
- Title:
- Photometry & line luminosities for ASASSN-14li
- Short Name:
- J/MNRAS/455/2918
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ground-based and Swift photometric and spectroscopic observations of the candidate tidal disruption event (TDE) ASASSN-14li, found at the centre of PGC 043234 (d~90 Mpc) by the All-Sky Automated Survey for SuperNovae (ASAS-SN). The source had a peak bolometric luminosity of L~10^44^ erg/s and a total integrated energy of E~7x10^50^ erg radiated over the ~6 months of observations presented. The UV/optical emission of the source is well fitted by a blackbody with roughly constant temperature of T~35000 K, while the luminosity declines by roughly a factor of 16 over this time. The optical/UV luminosity decline is broadly consistent with an exponential decline, L{prop.to}e^-t/t0^, with t_0_~60 d. ASASSN-14li also exhibits soft X-ray emission comparable in luminosity to the optical and UV emission but declining at a slower rate, and the X-ray emission now dominates. Spectra of the source show broad Balmer and helium lines in emission as well as strong blue continuum emission at all epochs. We use the discoveries of ASASSN-14li and ASASSN-14ae to estimate the TDE rate implied by ASAS-SN, finding an average rate of r~4.1x10^-5^/yr per galaxy with a 90 per cent confidence interval of (2.2-17.0)x10^-5^/yr per galaxy. ASAS-SN found roughly 1 TDE for every 70 Type Ia supernovae in 2014, a rate that is much higher than that of other surveys.
- ID:
- ivo://CDS.VizieR/J/ApJ/736/159
- Title:
- Photometry monitoring of the SN PTF10vdl
- Short Name:
- J/ApJ/736/159
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Palomar Transient Factory (PTF) is an optical wide-field variability survey carried out using a camera with a 7.8deg^2^ field of view mounted on the 48 inch Oschin Schmidt telescope at Palomar Observatory. One of the key goals of this survey is to conduct high-cadence monitoring of the sky in order to detect optical transient sources shortly after they occur. Here, we describe the real-time capabilities of the PTF and our related rapid multiwavelength follow-up programs, extending from the radio to the {gamma}-ray bands. We present as a case study observations of the optical transient PTF10vdl (SN 2010id), revealed to be a very young core-collapse (Type II-P) supernova having a remarkably low luminosity. Our results demonstrate that the PTF now provides for optical transients the real-time discovery and rapid-response follow-up capabilities previously reserved only for high-energy transients like gamma-ray bursts.
- ID:
- ivo://CDS.VizieR/J/ApJ/779/65
- Title:
- Photometry of LBGs, LAEs and GNBs at z~2.85
- Short Name:
- J/ApJ/779/65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a survey for z~2.85 Lyman-continuum (LyC) emission in the HS1549+1933 field and place constraints on the amount of ionizing radiation escaping from star-forming galaxies. Using a custom narrowband filter (NB3420) tuned to wavelengths just below the Lyman limit at z>=2.82, we probe the LyC spectral region of 49 Lyman break galaxies (LBGs) and 91 Ly{alpha} emitters (LAEs) spectroscopically confirmed at z>=2.82. Four LBGs and seven LAEs are detected in NB3420. Using V-band data probing the rest-frame nonionizing UV, we observe that many NB3420-detected galaxies exhibit spatial offsets between their LyC and nonionizing UV emission and are characterized by extremely blue NB3420-V colors, corresponding to low ratios of nonionizing to ionizing radiation (F_UV_/F_LyC_) that are in tension with current stellar population synthesis models. We measure average values of (F_UV_/F_LyC_) for our LBG and LAE samples, correcting for foreground galaxy contamination and H I absorption in the intergalactic medium. We find (F_UV_/F_LyC_)_corr_^LBG^=82+/-45 and (F_UV_/F_LyC_)_corr_^LAE^=7.4+/-3.6. These flux density ratios correspond, respectively, to relative LyC escape fractions of f_esc,rel_^LBG^=5%-8%, and f_esc,rel_^LAE^=18%-49% absolute LyC escape fractions of f_esc,rel_^LBG^=1%-2% and f_esc,rel_^LAE^=5%-15%, and a comoving LyC emissivity from star-forming galaxies of 8.8-15.0x10^24^ erg/s/Hz/Mpc^3^. In order to study the differential properties of galaxies with and without LyC detections, we analyze narrowband Ly{alpha} imaging and rest-frame near-infrared imaging, finding that while LAEs with LyC detections have lower Ly{alpha} equivalent widths on average, there is no substantial difference in the rest-frame near-infrared colors of LBGs or LAEs with and without LyC detections. These preliminary results are consistent with an orientation-dependent model where LyC emission escapes through cleared paths in a patchy interstellar medium.
- ID:
- ivo://CDS.VizieR/J/A+A/592/A40
- Title:
- Photometry of SN 2013gh and iPTF13dge
- Short Name:
- J/A+A/592/A40
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Temporal variability of narrow absorption lines in high-resolution spectra of Type Ia supernovae (SNe Ia) is studied to search for circumstellar matter. Time series which resolve the profiles of absorption lines such as NaI D or CaII H&K are expected to reveal variations due to photoionisation and subsequent recombination of the gases. The presence, composition, and geometry of circumstellar matter may hint at the elusive progenitor system of SNe Ia and could also affect the observed reddening law. To date, there are few known cases of time-varying NaI D absorption in SNe Ia, all of which occurred during relatively late phases of the supernova (SN) evolution. Photoionisation, however, is predicted to occur during the early phases of SNe Ia, when the supernovae peak in the ultraviolet. We attempt, therefore, to observe early-time absorption-line variations by obtaining high-resolution spectra of SNe before maximum light We have obtained photometry and high-resolution spectroscopy of SNe Ia 2013gh and iPTF 13dge, to search for absorption- line variations. Furthermore, we study interstellar absorption features in relation to the observed photometric colours of the SNe. Results. Both SNe display deep NaI D and CaII H&K absorption features. Furthermore, small but significant variations are detected in a feature of the NaI D profile of SN 2013gh. The variations are consistent with either geometric effects of rapidly moving or patchy gas clouds or photoionisation of NaI gas at R~=10^19^cm from the explosion. Our analysis indicates that it is necessary to focus on early phases to detect photoionisation effects of gases in the circumstellar medium of SNe Ia. Different absorbers such as NaI and CaII can be used to probe for matter at different distances from the SNe. The nondetection of variations during early phases makes it possible to put limits on the abundance of the species at those distances.
- ID:
- ivo://CDS.VizieR/J/MNRAS/455/1027
- Title:
- Photometry of the afterglow of GRB 130831A
- Short Name:
- J/MNRAS/455/1027
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Gamma-ray bursts (GRBs) are the most luminous explosions in the Universe, yet the nature and physical properties of their energy sources are far from understood. Very important clues, however, can be inferred by studying the afterglows of these events. We present optical and X-ray observations of GRB 130831A obtained by Swift, Chandra, Skynet, Reionization And Transients Infra-Red camera, Maidanak, International Scientific Optical-Observation Network, Nordic Optical Telescope, Liverpool Telescope and Gran Telescopio Canarias. This burst shows a steep drop in the X-ray light curve at ~10^5^ s after the trigger, with a power-law decay index of {alpha}~6. Such a rare behaviour cannot be explained by the standard forward shock (FS) model and indicates that the emission, up to the fast decay at 10^5^ s, must be of "internal origin", produced by a dissipation process within an ultrarelativistic outflow. We propose that the source of such an outflow, which must produce the X-ray flux for ~1 d in the cosmological rest frame, is a newly born magnetar or black hole. After the drop, the faint X-ray afterglow continues with a much shallower decay. The optical emission, on the other hand, shows no break across the X-ray steep decrease, and the late-time decays of both the X-ray and optical are consistent. Using both the X-ray and optical data, we show that the emission after ~10^5^ s can be explained well by the FS model. We model our data to derive the kinetic energy of the ejecta and thus measure the efficiency of the central engine of a GRB with emission of internal origin visible for a long time. Furthermore, we break down the energy budget of this GRB into the prompt emission, the late internal dissipation, the kinetic energy of the relativistic ejecta, and compare it with the energy of the associated supernova, SN 2013 fu.
- ID:
- ivo://CDS.VizieR/J/ApJ/880/120
- Title:
- Photometry of the tidal disruption event PS18kh
- Short Name:
- J/ApJ/880/120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of PS18kh, a tidal disruption event discovered at the center of SDSS J075654.53+341543.6 (d~322Mpc) by the Pan-STARRS Survey for Transients. Our data set includes pre-discovery survey data from Pan-STARRS, the All-sky Automated Survey for Supernovae, and the Asteroid Terrestrial-impact Last Alert System as well as high-cadence, multiwavelength follow-up data from ground-based telescopes and Swift, spanning from 56 days before peak light until 75days after. The optical/UV emission from PS18kh is well-fit as a blackbody with temperatures ranging from T~12000K to T~25000K and it peaked at a luminosity of L~8.8x10^43^erg/s. PS18kh radiated E=(3.45+/-0.22)x10^50^erg over the period of observation, with (1.42+/-0.20)x10^50^erg being released during the rise to peak. Spectra of PS18kh show a changing, boxy/double-peaked H{alpha} emission feature, which becomes more prominent over time. We use models of non-axisymmetric accretion disks to describe the profile of the H{alpha} line and its evolution. We find that at early times the high accretion rate leads the disk to emit a wind which modifies the shape of the line profile and makes it bell-shaped. At late times, the wind becomes optically thin, allowing the non-axisymmetric perturbations to show up in the line profile. The line-emitting portion of the disk extends from r_in_~60r_g_ to an outer radius of r_out_~1400r_g_ and the perturbations can be represented either as an eccentricity in the outer rings of the disk or as a spiral arm in the inner disk.
- ID:
- ivo://CDS.VizieR/J/ApJ/844/46
- Title:
- Photometry of the transient event iPTF16fnl
- Short Name:
- J/ApJ/844/46
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ground-based and Swift observations of iPTF16fnl, a likely tidal disruption event (TDE) discovered by the intermediate Palomar Transient Factory (iPTF) survey at 66.6Mpc. The light curve of the object peaked at an absolute mag M_g_=-17.2. The maximum bolometric luminosity (from optical and UV) was L_p_~(1.0+/-0.15)x10^43^erg/s, an order of magnitude fainter than any other optical TDE discovered so far. The luminosity in the first 60 days is consistent with an exponential decay, with L{propto}e^-(t-t_0_)/{tau}^, where t_0_=57631.0 (MJD) and {tau}~15 days. The X-ray shows a marginal detection at L_X_=2.4_-1.1_^1.9^x10^39^erg/s (Swift X-ray Telescope). No radio counterpart was detected down to 3{sigma}, providing upper limits for monochromatic radio luminosities of {nu}L_{nu}_<2.3x10^36^erg/s and {nu}L_{nu}_<1.7x10^37^erg/s (Very Large Array, 6.1 and 22GHz). The blackbody temperature, obtained from combined Swift UV and optical photometry, shows a constant value of 19000K. The transient spectrum at peak is characterized by broad HeII and H{alpha} emission lines, with FWHMs of about 14000km/s and 10000km/s, respectively. HeI lines are also detected at {lambda}{lambda}5875 and 6678. The spectrum of the host is dominated by strong Balmer absorption lines, which are consistent with a post-starburst (E+A) galaxy with an age of ~650Myr and solar metallicity. The characteristics of iPTF16fnl make it an outlier on both luminosity and decay timescales, as compared to other optically selected TDEs. The discovery of such a faint optical event suggests a higher rate of tidal disruptions, as low-luminosity events may have gone unnoticed in previous searches.