- ID:
- ivo://CDS.VizieR/J/A+A/514/A5
- Title:
- PAH luminous galaxies at z~1
- Short Name:
- J/A+A/514/A5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The NEP-deep survey, an extragalactic AKARI survey towards the north ecliptic pole (NEP), provides a comprehensive wavelength coverage from 2 to 24um using all 9 photometric bands of the infrared camera (IRC). It allows us to photometrically identify galaxies whose mid-IR emission is clearly dominated by PAHs. We propose a single-colour selection method to identify such galaxies, using two mid-IR flux ratios at 11-to-7um and 15-to-9um (PAH-to-continuum flux ratio in the rest frame), which are useful for identifying starburst galaxies at z~0.5 and 1, respectively. We perform a fitting of the spectral energy distributions (SEDs) from optical to mid-IR wavelengths, using an evolutionary starburst model with a proper treatment of radiative transfer (SBURT), in order to investigate their nature.
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- ID:
- ivo://CDS.VizieR/J/PASJ/65/103
- Title:
- PAH3.3um/IR luminosity for infrared galaxies
- Short Name:
- J/PASJ/65/103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- For star-forming galaxies, we investigated a global relation between the polycyclic aromatic hydrocarbon (PAH) emission luminosity at 3.3um, L_PAH3.3_, and the infrared (8-1000um) luminosity, L_IR_, to understand how the PAH 3.3um feature relates to star-formation activity. With AKARI, we performed near-infrared (2.5-5um) spectroscopy of 184 galaxies having L_IR_~10^8^-10^13^L_{sun}_. We classified the samples into infrared galaxies (IRGs: L_IR_<10^11^L_{sun}_), luminous infrared galaxies (LIRGs: L_IR_~10^11^-10^12^L_{sun}_ and ultra-luminous infrared galaxies (ULIRGs: L_IR_>10^12^L_{sun}_). We excluded sources likely to be contaminated by AGN activity, based on the rest-frame equivalent width of the PAH emission feature (<40nm) and the power-law index, representing the slope of continuum emission ({Gamma}>; F{nu}{prop.to}{lambda}^{Gamma}). Of these samples, 13 IRGs, 67 LIRGs, and 20 ULIRGs show the PAH emission feature at {lambda}_rest_=3.3um in their spectra. We find that the L_PAH3.3_/L_IR_ ratio considerably decreases toward the luminous end. Utilizing the mass and temperature of dust grains as well as the Br{alpha} emission for the galaxies, we discuss the cause of the relative decrease in the PAH emission with L_IR_.
- ID:
- ivo://CDS.VizieR/J/AJ/142/60
- Title:
- Palomar Transient Factory Orion Project
- Short Name:
- J/AJ/142/60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Palomar Transient Factory (PTF) Orion project is one of the experiments within the broader PTF survey, a systematic automated exploration of the sky for optical transients. Taking advantage of the wide (3.5{deg}x2.3{deg}) field of view available using the PTF camera installed at the Palomar 48 inch telescope, 40 nights were dedicated in 2009 December to 2010 January to perform continuous high-cadence differential photometry on a single field containing the young (7-10Myr) 25 Ori association. Little is known empirically about the formation of planets at these young ages, and the primary motivation for the project is to search for planets around young stars in this region. The unique data set also provides for much ancillary science. In this first paper, we describe the survey and the data reduction pipeline, and present some initial results from an inspection of the most clearly varying stars relating to two of the ancillary science objectives: detection of eclipsing binaries and young stellar objects.
- ID:
- ivo://CDS.VizieR/II/313
- Title:
- Palomar Transient Factory (PTF) photometric catalog 1.0
- Short Name:
- II/313
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We construct a photometrically calibrated catalog of non-variable sources from the Palomar Transient Factory (PTF) observations. The first version of this catalog presented here, the PTF photometric catalog 1.0, contains calibrated R_PTF_-filter magnitudes for ~2.1x10^7^ sources brighter than magnitude 19, over an area of ~11233{deg}^2^. The magnitudes are provided in the PTF photometric system, and the color of a source is required in order to convert these magnitudes into other magnitude systems. We estimate that the magnitudes in this catalog have typical accuracy of about 0.02mag with respect to magnitudes from the Sloan Digital Sky Survey. The median repeatability of our catalog's magnitudes for stars between 15 and 16mag, is about 0.01mag, and it is better than 0.03mag for 95% of the sources in this magnitude range. The main goal of this catalog is to provide reference magnitudes for photometric calibration of visible light observations. Subsequent versions of this catalog, which will be published incrementally online, will be extended to a larger sky area and will also include g_PTF_-filter magnitudes, as well as variability and proper motion information.
- ID:
- ivo://CDS.VizieR/J/ApJ/788/154
- Title:
- Palomar Transient Factory SNe IIn photometry
- Short Name:
- J/ApJ/788/154
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Interaction of supernova (SN) ejecta with the optically thick circumstellar medium (CSM) of a progenitor star can result in a bright, long-lived shock-breakout event. Candidates for such SNe include Type IIn and superluminous SNe. If some of these SNe are powered by interaction, then there should be a specific relation between their peak luminosity, bolometric light-curve rise time, and shock-breakout velocity. Given that the shock velocity during shock breakout is not measured, we expect a correlation, with a significant spread, between the rise time and the peak luminosity of these SNe. Here, we present a sample of 15 SNe IIn for which we have good constraints on their rise time and peak luminosity from observations obtained using the Palomar Transient Factory. We report on a possible correlation between the R-band rise time and peak luminosity of these SNe, with a false-alarm probability of 3%. Assuming that these SNe are powered by interaction, combining these observables and theory allows us to deduce lower limits on the shock-breakout velocity. The lower limits on the shock velocity we find are consistent with what is expected for SNe (i.e., ~10^4^ km/s). This supports the suggestion that the early-time light curves of SNe IIn are caused by shock breakout in a dense CSM. We note that such a correlation can arise from other physical mechanisms. Performing such a test on other classes of SNe (e.g., superluminous SNe) can be used to rule out the interaction model for a class of events.
- ID:
- ivo://CDS.VizieR/J/ApJ/782/42
- Title:
- Panchromatic observations of PTF11qcj
- Short Name:
- J/ApJ/782/42
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery, classification, and extensive panchromatic (from radio to X-ray) follow-up observations of PTF11qcj, a supernova (SN) discovered by the Palomar Transient Factory (PTF). Our observations with the Karl G. Jansky Very Large Array show that this event is radio-loud: PTF11qcj reached a radio peak luminosity comparable to that of the famous gamma-ray-burst-associated SN 1998bw (L_5GHz_{approx}10^29^erg/s/Hz). PTF11qcj is also detected in X-rays with the Chandra Observatory, and in the infrared band with Spitzer. Our multi-wavelength analysis probes the SN interaction with circumstellar material. The radio observations suggest a progenitor mass-loss rate of ~10^-4^M_{sun}_/yr*(v_w_/1000km/s), and a velocity of {approx}0.3-0.5c for the fastest moving ejecta (at {approx}10 days after explosion). However, these estimates are derived assuming the simplest model of SN ejecta interacting with a smooth circumstellar wind, and do not account for possible inhomogeneities in the medium and asphericity of the explosion. The radio data show deviations from such a simple model, as well as a late-time re-brightening. The X-ray flux from PTF11qcj is compatible with the high-frequency extrapolation of the radio synchrotron emission (within the large uncertainties). A light echo from pre-existing dust is in agreement with our infrared data. Our pre-explosion data from the PTF suggest that a precursor eruption of absolute magnitude M_r_{approx}-13mag may have occurred {approx}2.5yr prior to the SN explosion. Overall, PTF11qcj fits the expectations from the explosion of a Wolf-Rayet star. Precursor eruptions may be a feature characterizing the final pre-explosion evolution of such stars.
- ID:
- ivo://CDS.VizieR/J/A+A/644/A163
- Title:
- Pan-STARRS lens candidates from neural networks
- Short Name:
- J/A+A/644/A163
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a systematic search for wide-separation (with Einstein radius ~1.5"), galaxy-scale strong lenses in the 30000 sq.deg of the Pan-STARRS 3pi survey on the Northern sky. With long time delays of a few days to weeks, these types of systems are particularly well-suited for catching strongly lensed supernovae with spatially-resolved multiple images and offer new insights on early-phase supernova spectroscopy and cosmography. We produced a set of realistic simulations by painting lensed COSMOS sources on Pan-STARRS image cutouts of lens luminous red galaxies (LRGs) with redshift and velocity dispersion known from the sloan digital sky survey (SDSS). First, we computed the photometry of mock lenses in gri bands and applied a simple catalog-level neural network to identify a sample of 1050207 galaxies with similar colors and magnitudes as the mocks. Second, we trained a convolutional neural network (CNN) on Pan-STARRS gri image cutouts to classify this sample and obtain sets of 105760 and 12382 lens candidates with scores of pCNN>0.5 and >0.9, respectively. Extensive tests showed that CNN performances rely heavily on the design of lens simulations and the choice of negative examples for training, but little on the network architecture. The CNN correctly classified 14 out of 16 test lenses, which are previously confirmed lens systems above the detection limit of Pan-STARRS. Finally, we visually inspected all galaxies with pCNN>0.9 to assemble a final set of 330 high-quality newly-discovered lens candidates while recovering 23 published systems. For a subset, SDSS spectroscopy on the lens central regions proves that our method correctly identifies lens LRGs at z~0.1-0.7. Five spectra also show robust signatures of high-redshift background sources, and Pan-STARRS imaging confirms one of them as a quadruply-imaged red source at z_s_=1.185, which is likely a recently quenched galaxy strongly lensed by a foreground LRG at z_d_=0.3155. In the future, high-resolution imaging and spectroscopic follow-up will be required to validate Pan-STARRS lens candidates and derive strong lensing models. We also expect that the efficient and automated two-step classification method presented in this paper will be applicable to the ~4 mag deeper gri stacks from the Rubin Observatory Legacy Survey of Space and Time (LSST) with minor adjustments.
- ID:
- ivo://CDS.VizieR/J/ApJ/794/23
- Title:
- Pan-STARRS1 transients optical photometry
- Short Name:
- J/ApJ/794/23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the past decade, several rapidly evolving transients have been discovered whose timescales and luminosities are not easily explained by traditional supernovae (SNe) models. The sample size of these objects has remained small due, at least in part, to the challenges of detecting short timescale transients with traditional survey cadences. Here we present the results from a search within the Pan-STARRS1 Medium Deep Survey (PS1-MDS) for rapidly evolving and luminous transients. We identify 10 new transients with a time above half-maximum (t_1/2_) of less than 12 days and -16.5>M>-20 mag. This increases the number of known events in this region of SN phase space by roughly a factor of three. The median redshift of the PS1-MDS sample is z=0.275 and they all exploded in star-forming galaxies. In general, the transients possess faster rise than decline timescale and blue colors at maximum light (g_P1_-r_P1_<~-0.2). Best-fit blackbodies reveal photospheric temperatures/radii that expand/cool with time and explosion spectra taken near maximum light are dominated by a blue continuum, consistent with a hot, optically thick, ejecta. We find it difficult to reconcile the short timescale, high peak luminosity (L>10^43^ erg/s), and lack of UV line blanketing observed in many of these transients with an explosion powered mainly by the radioactive decay of ^56^Ni. Rather, we find that many are consistent with either (1) cooling envelope emission from the explosion of a star with a low-mass extended envelope that ejected very little (<0.03 M_{sun}_) radioactive material, or (2) a shock breakout within a dense, optically thick, wind surrounding the progenitor star. After calculating the detection efficiency for objects with rapid timescales in the PS1-MDS we find a volumetric rate of 4800-8000 events/yr/Gpc^3^ (4%-7% of the core-collapse SN rate at z=0.2).
- ID:
- ivo://CDS.VizieR/J/A+A/493/L27
- Title:
- Parallaxes of 10 ultracool subdwarfs
- Short Name:
- J/A+A/493/L27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We measure absolute trigonometric parallaxes and proper motions with respect to many background galaxies for a sample of ten ultracool subdwarfs. Observations were taken in the H-band with the OMEGA2000 camera on the 3.5 m-telescope at Calar Alto, Spain during a time period of 3.5-years. For the first time, the reduction of the astrometric measurements was carried out directly with respect to background galaxies. We obtained absolute parallaxes with mean errors ranging between 1 and 3mas.
- ID:
- ivo://CDS.VizieR/J/AJ/162/13
- Title:
- Parameters estimation for 173 eclipsing binaries
- Short Name:
- J/AJ/162/13
- Date:
- 21 Mar 2022 00:50:18
- Publisher:
- CDS
- Description:
- High precision CCD observations of six totally eclipsing contact binaries were presented and analyzed. It is found that only one target is an A-type contact binary (V429Cam), while the others are W-type contact ones. By analyzing the times of light minima, we discovered that two of them exhibit secular period increase while three manifest long-term period decrease. For V1033Her, a cyclic variation superimposed on the long-term increase was discovered. By comparing the Gaia distances with those calculated by the absolute parameters of 173 contact binaries, we found that the Gaia distance can be applied to estimate the absolute parameters for most contact binaries. The absolute parameters of our six targets were estimated using their Gaia distances. The evolutionary status of contact binaries was studied, and we found that the A- and W-subtype contact binaries may have different formation channels. The relationship between the spectroscopic and photometric mass ratios for 101 contact binaries was presented. It was discovered that the photometric mass ratios are in good agreement with the spectroscopic ones for almost all of the totally eclipsing systems, which is corresponding to the results derived by Pribulla et al. and Terrell & Wilson.
