- ID:
- ivo://CDS.VizieR/J/AJ/162/47
- Title:
- UV luminosity in ~25000 2<z<9 galaxies
- Short Name:
- J/AJ/162/47
- Date:
- 16 Mar 2022 00:17:16
- Publisher:
- CDS
- Description:
- Here we provide the most comprehensive determinations of the rest-frame UV luminosity function (LF) available to date with the Hubble Space Telescope (HST) at z~2-9. Essentially all of the noncluster extragalactic legacy fields are utilized, including the Hubble Ultra Deep Field, the Hubble Frontier Fields parallel fields, and all five CANDELS fields, for a total survey area of 1136arcmin^2^. Our determinations include galaxies at z~2-3 leveraging the deep HDUV, UVUDF, and ERS WFC3/UVIS observations available over an ~150arcmin^2^ area in the GOODS-North and GOODS-South regions. All together, our collective samples include >24000 sources, >2.3x larger than previous selections with HST. We identify 5766, 6332, 7240, 3449, 1066, 601, 246, and 33 sources at z~2, 3, 4, 5, 6, 7, 8, and 9, respectively. Combining our results with an earlier z~10 LF determination by Oesch et al., we quantify the evolution of the UV LF. Our results indicate that there is (1) a smooth flattening of the faint-end slope {alpha} from {alpha}~-2.4 at z~10 to {alpha}~-1.5 at z~2, (2) minimal evolution in the characteristic luminosity M* at z>~2.5, and (3) a monotonic increase in the normalization log_10_\{phi}* from z~10 to 2, which can be well described by a simple second-order polynomial, consistent with an "accelerated" evolution scenario. We find that each of these trends (from z~10 to 2.5 at least) can be readily explained on the basis of the evolution of the halo mass function and a simple constant star formation efficiency model.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/810/71
- Title:
- UV mag of candidate galaxies at 3~<z~<8.5
- Short Name:
- J/ApJ/810/71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a robust measurement and analysis of the rest-frame ultraviolet (UV) luminosity functions at z=4-8. We use deep Hubble Space Telescope imaging over the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey/GOODS fields, the Hubble Ultra Deep Field, and the Hubble Frontier Field deep parallel observations near the Abell 2744 and MACS J0416.1-2403 clusters. The combination of these surveys provides an effective volume of 0.6-1.2x10^6^Mpc^3^ over this epoch, allowing us to perform a robust search for faint (M_UV_=-18) and bright (M_UV_<-21) high-redshift galaxies. We select candidate galaxies using a well-tested photometric redshift technique with careful screening of contaminants, finding a sample of 7446 candidate galaxies at 3.5<z<8.5, with >1000 galaxies at z~6-8. We measure both a stepwise luminosity function for candidate galaxies in our redshift samples, and a Schechter function, using a Markov Chain Monte Carlo analysis to measure robust uncertainties. At the faint end, our UV luminosity functions agree with previous studies, yet we find a higher abundance of UV-bright candidate galaxies at z>=6.
- ID:
- ivo://CDS.VizieR/J/ApJ/883/147
- Title:
- UV-NIR LCs of the energetic H-stripped SN2016coi
- Short Name:
- J/ApJ/883/147
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present comprehensive observations and analysis of the energetic H-stripped SN 2016coi (a.k.a. ASASSN-16fp), spanning the {gamma}-ray through optical and radio wavelengths, acquired within the first hours to ~420 days post explosion. Our observational campaign confirms the identification of He in the supernova (SN) ejecta, which we interpret to be caused by a larger mixing of Ni into the outer ejecta layers. By modeling the broad bolometric light curve, we derive a large ejecta-mass-to-kinetic-energy ratio (M_ej_~4-7M_{sun}_, E_k_~(7-8)x10^51^erg). The small [CaII]{lambda}{lambda}7291,7324 to [OI]{lambda}{lambda}6300,6364 ratio (~0.2) observed in our late-time optical spectra is suggestive of a large progenitor core mass at the time of collapse. We find that SN 2016coi is a luminous source of X-rays (L_X_>10^39^erg/s in the first ~100 days post explosion) and radio emission (L_8.5GHz_~7x10^27^erg/s/Hz at peak). These values are in line with those of relativistic SNe (2009bb, 2012ap). However, for SN 2016coi, we infer substantial pre-explosion progenitor mass loss with a rate dM/dt~(1-2)x10^-4^M_{sun}_/yr and a sub-relativistic shock velocity v_sh_~0.15c, which is in stark contrast with relativistic SNe and similar to normal SNe. Finally, we find no evidence for a SN- associated shock breakout {gamma}-ray pulse with energy E_{gamma}_>2x10^46^erg. While we cannot exclude the presence of a companion in a binary system, taken together, our findings are consistent with a massive single-star progenitor that experienced large mass loss in the years leading up to core collapse, but was unable to achieve complete stripping of its outer layers before explosion.
- ID:
- ivo://CDS.VizieR/J/ApJ/892/93
- Title:
- UV-NIR monitoring campaign of NGC 4395
- Short Name:
- J/ApJ/892/93
- Date:
- 19 Jan 2022 09:00:14
- Publisher:
- CDS
- Description:
- We present a variability study of the lowest-luminosity Seyfert 1 nucleus of the galaxy NGC 4395 based on photometric monitoring campaigns in 2017 and 2018. Using 22 ground-based and space telescopes, we monitored NGC 4395 with a ~5-minute cadence during a period of 10 days and obtained light curves in the ultraviolet (UV), V, J, H, and K/K_s_ bands, as well as narrowband H{alpha}. The rms variability is ~0.13mag in the Swift UVM2 and V filter light curves, decreasing down to ~0.01mag in the K filter. After correcting for the continuum contribution to the H{alpha} narrow band, we measured the time lag of the H{alpha} emission line with respect to the V-band continuum as 55_-31_^+27^-122_-67_^+33^min in 2017 and 49_-14_^+15^-83_-14_^+13^min in 2018, depending on assumptions about the continuum variability amplitude in the H{alpha} narrow band. We obtained no reliable measurements for the continuum-to-continuum lag between UV and V bands and among near-IR bands, owing to the large flux uncertainty of UV observations and the limited time baseline. We determined the active galactic nucleus (AGN) monochromatic luminosity at 5100{AA}, {lambda}L_{lambda}_=(5.75+/-0.40)x10^39^erg/s, after subtracting the contribution of the nuclear star cluster. While the optical luminosity of NGC 4395 is two orders of magnitude lower than that of other reverberation-mapped AGNs, NGC 4395 follows the size-luminosity relation, albeit with an offset of 0.48dex (>=2.5{sigma}) from the previous best-fit relation of Bentz+ 2013ApJ...767..149B
- ID:
- ivo://CDS.VizieR/J/ApJ/851/L21
- Title:
- UV-NIR obs. compilation of GW170817 counterpart
- Short Name:
- J/ApJ/851/L21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first effort to aggregate, homogenize, and uniformly model the combined ultraviolet, optical, and near-infrared data set for the electromagnetic counterpart of the binary neutron star merger GW170817. By assembling all of the available data from 18 different papers and 46 different instruments, we are able to identify and mitigate systematic offsets between individual data sets and to identify clear outlying measurements, with the resulting pruned and adjusted data set offering an opportunity to expand the study of the kilonova. The unified data set includes 647 individual flux measurements, spanning 0.45-29.4d post-merger, and thus has greater constraining power for physical models than any single data set. We test a number of semi-analytical models and find that the data are well modeled with a three-component kilonova model: a "blue" lanthanide-poor component ({kappa}=0.5cm^2^/g) with M_ej_~0.020M_{sun}_ and v_ej_~0.27c; an intermediate opacity "purple" component ({kappa}=3cm^2^/g) with M_ej_~0.047M_{sun}_ and v_ej_~0.15c; and a "red" lanthanide-rich component ({kappa}=10cm^2^/g) with M_ej_~0.011M_{sun}_ and v_ej_~0.14c. We further explore the possibility of ejecta asymmetry and its impact on the estimated parameters. From the inferred parameters we draw conclusions about the physical mechanisms responsible for the various ejecta components, the properties of the neutron stars, and, combined with an up-to-date merger rate, the implications for r-process enrichment via this channel. To facilitate future studies of this keystone event we make the unified data set and our modeling code public.
- ID:
- ivo://CDS.VizieR/J/AJ/113/1011
- Title:
- UV Observations of the SMC
- Short Name:
- J/AJ/113/1011
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A mosaic of four UIT (Ultraviolet Imaging Telescope) far-UV (FUV) ({lambda}_(eff)_=1620{AA}) images, with derived stellar and H II region photometry, is presented for most of the Bar of the SMC. The UV morphology of the SMC's Bar shows that recent star formation there has left striking features including: (a) four concentrations of UV-bright stars spread from northeast to southwest at nearly equal (~30arcmin=0.5kpc) spacings; (b) one of the concentrations, near DEM 55, comprises a well-defined 8-arcmin diameter ring surrounded by a larger H{alpha} ring, suggestive of sequential star formation. FUV PSF photometry is obtained for 11,306 stars in the FUV images, resulting in magnitudes m(162). We present a FUV luminosity function for the SMC Bar, complete to m(162)~14.5. Detected objects are well correlated with other SMC Population I material; of 711 H{alpha} emission-line stars and small nebulae within the UIT fields of view, 520 are identified with FUV sources. The FUV photometry is compared with available ground-based catalogs of supergiants, yielding 191 detections of 195 supergiants with spectral type earlier than F0 in the UIT fields. The (m(162)-V) color for supergiants is a sensitive measure of spectral type. The bluest observed colors for each type agree well with colors computed from unreddened Galactic spectral atlas stars for types earlier than about A0; for later spectral types the observed SMC stars range significantly bluer, as predicted by comparison of low-metallicity and Galactic-composition models. Redder colors for some stars of all spectral types are attributed to the strong FUV extinction arising from even small amounts of SMC dust. Internal SMC reddenings are determined for all catalog stars. All stars with E(B-V)>0.15 are within regions of visible H{alpha} emission. FUV photometry for 42 H{alpha} -selected H II regions in the SMC Bar is obtained for stars and for total emission (as measured in H II-region-sized apertures). The flux-weighted average ratio of total to stellar FUV flux is 2.15; consideration of the stellar FUV luminosity function indicates that most of the excess total flux is due to scattered FUV radiation, rather than stars fainter than m(162)=14.5. Both stellar and total emission are well correlated with H{alpha} fluxes measured by Kennicutt and Hodge (1986ApJ...306..130K), yielding FUV/H{alpha} flux ratios that are consistent with models of SMC metallicity, ages from 1-5Myr, and moderate (E(B-V)=0.0-0.1mag) internal SMC extinction. (Copyright) 1997 American Astronomical Society.
- ID:
- ivo://CDS.VizieR/J/ApJ/900/46
- Title:
- UV, optical and IR light curve of supernova SN2019dge
- Short Name:
- J/ApJ/900/46
- Date:
- 11 Mar 2022 14:13:09
- Publisher:
- CDS
- Description:
- We present observations of ZTF18abfcmjw (SN2019dge), a helium-rich supernova with a fast-evolving light curve indicating an extremely low ejecta mass (~0.33M{sun}) and low kinetic energy (~1.3x1050erg). Early-time (<4days after explosion) photometry reveals evidence of shock cooling from an extended helium-rich envelope of ~0.1M{sun} located ~1.2x1013cm from the progenitor. Early-time HeII line emission and subsequent spectra show signatures of interaction with helium-rich circumstellar material, which extends from >~5x1013cm to >~2x1016cm. We interpret SN2019dge as a helium-rich supernova from an ultra-stripped progenitor, which originates from a close binary system consisting of a mass-losing helium star and a low-mass main-sequence star or a compact object (i.e., a white dwarf, a neutron star, or a black hole). We infer that the local volumetric birth rate of 19dge-like ultra-stripped SNe is in the range of 1400-8200/Gpc^3^/yr (i.e., 2%-12% of core-collapse supernova rate). This can be compared to the observed coalescence rate of compact neutron star binaries that are not formed by dynamical capture.
- ID:
- ivo://CDS.VizieR/J/ApJ/813/30
- Title:
- UV-Optical light curves of the SNIa iPTF14bdn
- Short Name:
- J/ApJ/813/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ultraviolet (UV) and optical photometry and spectra of the 1999aa-like supernova (SN) iPTF14bdn. The UV data were observed using the Swift Ultraviolet/Optical Telescope (UVOT) and constitute the first UV spectral series of a 1999aa-like SN. From the photometry, we measure {Delta}m_15_(B)=0.84+/-0.05mag and blue UV colors at epochs earlier than -5 days. The spectra show that the early-time blue colors are the result of less absorption between 2800-3200{AA} than is present in normal SNe Ia. Using model spectra fits of the data at -10 and +10days, we identify the origin of this spectral feature to be a temperature effect in which doubly ionized iron group elements create an opacity "window". We determine that the detection of high temperatures and large quantities of iron group elements at early epochs imply the mixing of a high Ni mass into the outer layers of the SN ejecta. We also identify the source of the I-band secondary maximum in iPTF14bdn to be the decay of FeIII to FeII, as is seen in normal SNe Ia.
- ID:
- ivo://CDS.VizieR/J/MNRAS/449/1921
- Title:
- UV/optical/NIR photometry for Type Ibn SNe
- Short Name:
- J/MNRAS/449/1921
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ultraviolet, optical and near-infrared data of the Type Ibn supernovae (SNe) 2010al and 2011hw. SN 2010al reaches an absolute magnitude at peak of M_R_=-18.86+/-0.21. Its early light curve shows similarities with normal SNe Ib, with a rise to maximum slower than most SNe Ibn. The spectra are dominated by a blue continuum at early stages, with narrow P-Cygni HeI lines indicating the presence of a slow-moving, He-rich circumstellar medium. At later epochs, the spectra well match those of the prototypical SN Ibn 2006jc, although the broader lines suggest that a significant amount of He was still present in the stellar envelope at the time of the explosion. SN 2011hw is somewhat different. It was discovered after the first maximum, but the light curve shows a double peak. The absolute magnitude at discovery is similar to that of the second peak (M_R_=-18.59+/-0.25), and slightly fainter than the average of SNe Ibn. Though the spectra of SN 2011hw are similar to those of SN 2006jc, coronal lines and narrow Balmer lines are clearly detected. This indicates substantial interaction of the SN ejecta with He-rich, but not H-free, circumstellar material. The spectra of SN 2011hw suggest that it is a transitional SN Ibn/IIn event similar to SN 2005la. While for SN 2010al the spectrophotometric evolution favours a H-deprived Wolf-Rayet progenitor (of WN-type), we agree with the conclusion of Smith et al. that the precursor of SN 2011hw was likely in transition from a luminous blue variable to an early Wolf-Rayet (Ofpe/WN_9_) stage.
- ID:
- ivo://CDS.VizieR/J/ApJ/872/198
- Title:
- UV-Opt LC of tidal disruption flare AT2018zr
- Short Name:
- J/ApJ/872/198
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Zwicky Transient Facility (ZTF) observations of the tidal disruption flare AT2018zr/PS18kh reported by Holoien+ (2019ApJ...880..120H) and detected during ZTF commissioning. The ZTF light curve of the tidal disruption event (TDE) samples the rise-to-peak exceptionally well, with 50 days of g- and r-band detections before the time of maximum light. We also present our multi-wavelength follow-up observations, including the detection of a thermal (kT~100eV) X-ray source that is two orders of magnitude fainter than the contemporaneous optical/UV blackbody luminosity, and a stringent upper limit to the radio emission. We use observations of 128 known active galactic nuclei (AGNs) to assess the quality of the ZTF astrometry, finding a median host-flare distance of 0.2" for genuine nuclear flares. Using ZTF observations of variability from known AGNs and supernovae we show how these sources can be separated from TDEs. A combination of light-curve shape, color, and location in the host galaxy can be used to select a clean TDE sample from multi-band optical surveys such as ZTF or the Large Synoptic Survey Telescope.
