Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/865/106
- Title:
- SUPER GOODS. III. ALMA data for SCUBA-2 sources
- Short Name:
- J/ApJ/865/106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze the >4{sigma} sources in the most sensitive 100arcmin^2^ area (rms<0.56mJy) of a SCUBA-2 850{mu}m survey of the GOODS-S and present the 75 band-7 ALMA sources (>4.5{sigma}) obtained from high-resolution interferometric follow-up observations. The raw SCUBA-2 >4{sigma} limit is fainter than 2.25mJy throughout this region, and deboosting corrections would lower this further. Of the 53 SCUBA-2 sources in this sample, only five have no ALMA detections, while 13% (68% confidence range 7%-19%) have multiple ALMA counterparts. Color-based high-redshift dusty galaxy selection techniques find at most 55% of the total ALMA sample. In addition to using literature spectroscopic and optical/near-infrared photometric redshifts, we estimate far infrared photometric redshifts based on an Arp 220 template. We identify seven z>~4 candidates. We see the expected decline with redshift of the 4.5 and 24{mu}m to 850{mu}m flux ratios, confirming these as good diagnostics of z>~4 candidates. We visually classify 52 ALMA sources, finding 44% (68% confidence range 35%-53%) to be apparent mergers. We calculate rest-frame 2-8keV and 8-28keV luminosities using the 7Ms Chandra X-ray image. Nearly all of the ALMA sources detected at 0.5-2keV are consistent with a known X-ray luminosity to 850{mu}m flux relation for star-forming galaxies, while most of those detected at 2-7keV are moderate-luminosity AGNs that lie just above the 2-7keV detection threshold. The latter largely have substantial obscurations of logN_H_=23-24cm^-2^, but two of the high-redshift candidates may even be Compton thick.
- ID:
- ivo://CDS.VizieR/J/ApJ/837/139
- Title:
- SUPER GOODS. I. Ultradeep SCUBA-2 survey
- Short Name:
- J/ApJ/837/139
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this first paper in the SUPER GOODS series on powerfully star-forming galaxies in the two GOODS fields, we present a deep SCUBA-2 survey of the GOODS-N at both 850 and 450{mu}m (central rms noise of 0.28mJy and 2.6mJy, respectively). In the central region, the 850{mu}m observations cover the GOODS-N to near the confusion limit of ~1.65mJy, while over a wider 450arcmin^2^ region-well complemented by Herschel far-infrared imaging-they have a median 4{sigma} limit of 3.5mJy. We present >=4{sigma} catalogs of 186 850{mu}m and 31 450{mu}m selected sources. We use interferometric observations from the Submillimeter Array (SMA) and the Karl G. Jansky Very Large Array (VLA) to obtain precise positions for 114 SCUBA-2 sources (28 from the SMA, all of which are also VLA sources). We present new spectroscopic redshifts and include all existing spectroscopic or photometric redshifts. We also compare redshifts estimated using the 20cm/850{mu}m and the 250cm/850{mu}m flux ratios. We show that the redshift distribution increases with increasing flux, and we parameterize the dependence. We compute the star formation history and the star formation rate (SFR) density distribution functions in various redshift intervals, finding that they reach a peak at z=2-3 before dropping to higher redshifts. We show that the number density per unit volume of SFR>~500M_{sun}_/yr galaxies measured from the SCUBA-2 sample does not change much relative to that of lower SFR galaxies from UV selected samples over z=2-5, suggesting that, apart from changes in the normalization, the shape in the number density as a function of SFR is invariant over this redshift interval.
- ID:
- ivo://CDS.VizieR/J/ApJ/887/23
- Title:
- SUPER GOODS. IV. 850um data of CDFS X-ray sources
- Short Name:
- J/ApJ/887/23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Chandra Deep Field (CDF)-S is the deepest X-ray image available and will remain so for the near future. We provide a spectroscopic (64.5%; 64% with spectral classifications) and photometric redshift catalog for the full 7Ms sample, but much of our analysis focuses on the central (off-axis angles <5.7') region, which contains a large, faint ALMA sample of 75 >4.5{sigma} 850{mu}m sources. We measure the 850{mu}m fluxes at the X-ray positions using the ALMA images, where available, or an ultradeep SCUBA-2 map. We find that the full X-ray sample produces ~10% of the 850{mu}m extragalactic background light. We separate the submillimeter-detected X-ray sources into star-forming galaxies and active galactic nuclei (AGNs) using a star formation rate (SFR) versus X-ray luminosity calibration for high-SFR galaxies. We confirm this separation using the X-ray photon indices. We measure the X-ray fluxes at the accurate positions of the 75 ALMA sources and detect 70% at >3{sigma} in either the 0.5-2 or 2-7keV bands. However, many of these may produce both their X-ray and submillimeter emission by star formation. Indeed, we find that only 20% of the ALMA sources have intermediate X-ray luminosities (rest-frame 8-28 keV luminosities of 10^42.5^-10^44^erg/s), and none has a high X-ray luminosity (>10^44^erg/s). Conversely, after combining the CDF-S with the CDF-N, we find extreme star formation (SFR>300M_{sun}_/yr) in some intermediate X-ray luminosity sources but not in any high X-ray luminosity sources. We argue that the quenching of star formation in the most luminous AGNs may be a consequence of the clearing of gas in these sources.
- ID:
- ivo://CDS.VizieR/J/A+A/479/49
- Title:
- Supernova rates from STRESS
- Short Name:
- J/A+A/479/49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To measure the supernova (SN) rates at intermediate redshift we performed a search, the Southern inTermediate Redshift ESO Supernova Search (STRESS). Unlike most of the current high redshift SN searches, this survey was specifically designed to estimate the rate for both type Ia and core collapse (CC) SNe. We counted the SNe discovered in a selected galaxy sample measuring SN rate per unit blue band luminosity. Our analysis is based on a sample of ~43000 galaxies and on 25 spectroscopically confirmed SNe plus 64 selected SN candidates. Our approach is aimed at obtaining a direct comparison of the high redshift and local rates and at investigating the dependence of the rates on specific galaxy properties, most notably their colour.
- ID:
- ivo://CDS.VizieR/J/ApJ/763/73
- Title:
- Surface density profiles of GOODS-South galaxies
- Short Name:
- J/ApJ/763/73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present stellar mass surface density profiles of a mass-selected sample of 177 galaxies at 0.5<z<2.5, obtained using very deep Hubble Space Telescope optical and near-infrared data over the GOODS-South field, including recent CANDELS data. Accurate stellar mass surface density profiles have been measured for the first time for a complete sample of high-redshift galaxies more massive than 10^10.7^M_{sun}_. The key advantage of this study compared to previous work is that the surface brightness profiles are deconvolved for point-spread function smoothing, allowing accurate measurements of the structure of the galaxies. The surface brightness profiles account for contributions from complex galaxy structures such as rings and faint outer disks. Mass profiles are derived using radial rest-frame ug color profiles and a well-established empirical relation between these colors and the stellar mass-to-light ratio. We derive stellar half-mass radii from the mass profiles, and find that these are on average ~25% smaller than rest-frame g-band half-light radii. This average size difference of 25% is the same at all redshifts, and does not correlate with stellar mass, specific star formation rate, effective surface density, S\'ersic index, or galaxy size. Although on average the difference between half-mass size and half-light size is modest, for approximately 10% of massive galaxies this difference is more than a factor of two. These extreme galaxies are mostly extended, disk-like systems with large central bulges. These results are robust, but could be impacted if the central dust extinction becomes high. ALMA observations can be used to explore this possibility. These results provide added support for galaxy growth scenarios wherein massive galaxies at these epochs grow by accretion onto their outer regions.
- ID:
- ivo://CDS.VizieR/J/A+A/387/26
- Title:
- Surface photometry in 7 nearby clusters
- Short Name:
- J/A+A/387/26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the first paper of a series investigating the scaling relations of early-type galaxies in clusters. Here we illustrate the multi-band imagery and the image reduction and calibration procedures relative to the whole sample of 22 clusters at 0.05<~z<~0.25. We also present detailed surface photometry of 312 early-type galaxies in 7 clusters (A1069, A119, A1983, A2151, A2670, A3125 and DC2103) in the first redshift bin, z=0.025-0.075. We give for each galaxy the complete set of luminosity and geometrical profiles, and a number of global, photometric and morphological parameters. They have been evaluated taking into account the effects of seeing. Internal consistency checks and comparisons with data in the literature confirm the quality of our analysis. These data, together with the spectroscopic ones presented in the second paper of the series, will provide the local calibration of the scaling relations.
- ID:
- ivo://CDS.VizieR/J/ApJS/177/39
- Title:
- Survey of low-redshift OVI absorbers
- Short Name:
- J/ApJS/177/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using high-resolution ultraviolet spectra of 16 low-z QSOs obtained with the E140M echelle mode of the Space Telescope Imaging Spectrograph, we study the physical conditions and statistics of OVI absorption in the intergalactic medium (IGM) at z<0.5. We identify 51 intervening (z_abs_<z_QSO_) OVI systems comprising 77 individual components, and we find 14 "proximate" systems (z_abs_~z_QSO_) containing 34 components. For intervening systems (components) with rest-frame equivalent width W_r_>30m{AA}, the number of OVI absorbers per unit redshift dN/dz=15.6^+2.9^_-2.4_(21.0^+3.2^_-2.8_), and this decreases to dN/dz=0.9^+1.0^_-0.5_(0.3^+0.7^_-0.3_) for W_r_>300m{AA}. The number per redshift increases steeply as z_abs_ approaches z_QSO_; we find that dN/dz is ~3-10 times higher within 2500km/s of z_QSO_. The most striking difference between intervening and proximate systems is that some proximate absorbers have substantially lower HI/OVI ratios.
- ID:
- ivo://CDS.VizieR/J/A+A/296/665
- Title:
- Survey of optically variables QSOs
- Short Name:
- J/A+A/296/665
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a survey for variable QSOs carried out for 15 years with the UK Schmidt telescope, using IIIaJ plates exposed behind a Schott GG395 filter. Objects brighter than B=21.0 on a reference plate and displaying a peak to peak amplitude of variability larger than B=0.35mag are selected. Plates in U, V, R and I were also obtained.
- ID:
- ivo://CDS.VizieR/J/ApJ/864/45
- Title:
- Survey of X-ray emission from superluminous SNe
- Short Name:
- J/ApJ/864/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from a sensitive X-ray survey of 26 nearby hydrogen-poor superluminous supernovae (SLSNe-I) with Swift, Chandra, and XMM. This data set constrains the SLSN evolution from a few days until ~2000d after explosion, reaching a luminosity limit Lx~10^40^erg/s and revealing the presence of significant X-ray emission possibly associated with PTF 12dam. No SLSN-I is detected above Lx~10^41^erg/s, suggesting that the luminous X-ray emission Lx~10^45^erg/s associated with SCP 60F6 is not common among SLSNe-I. We constrain the presence of off-axis gamma-ray burst (GRB) jets, ionization breakouts from magnetar engines and the density in the sub-parsec environments of SLSNe-I through inverse Compton emission. The deepest limits rule out the weakest uncollimated GRB outflows, suggesting that if the similarity of SLSNe-I with GRB/SNe extends to their fastest ejecta, then SLSNe-I are either powered by energetic jets pointed far away from our line of sight ({theta}>30{deg}), or harbor failed jets that do not successfully break through the stellar envelope. Furthermore, if a magnetar central engine is responsible for the exceptional luminosity of SLSNe-I, our X-ray analysis favors large magnetic fields B>2x10^14^G and ejecta masses M_ej_>3M_{sun}_, in agreement with optical/UV studies. Finally, we constrain the pre-explosion mass-loss rate of stellar progenitors of SLSNe-I. For PTF 12dam we infer dM/dt<2x10^-5^M_{sun}_/yr, suggesting that the SN shock interaction with an extended circumstellar medium is unlikely to supply the main source of energy powering the optical transient and that some SLSN-I progenitors end their lives as compact stars surrounded by a low-density medium similar to long GRBs and type Ib/c SNe.