- ID:
- ivo://CDS.VizieR/J/MNRAS/371/221
- Title:
- Deep Chandra survey of the Groth Strip. II.
- Short Name:
- J/MNRAS/371/221
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we discuss the optical and X-ray spectral properties of the sources detected in a single 200-ks Chandra pointing in the Groth-Westphal Strip region. A wealth of optical photometric and spectroscopic data are available in this field providing optical identifications and redshift determinations for the X-ray population. The optical photometry and spectroscopy used here are primarily from the Deep Extragalactic Evolutionary Probe 2 (DEEP2) survey with additional redshifts obtained from the literature. These are complemented with the deeper (r>>26mag) multiwaveband data (ugriz) from the Canada-France-Hawaii Telescope Legacy Survey to estimate photometric redshifts and to optically identify sources fainter than the DEEP2 magnitude limit (R_AB_>>24.5mag). We focus our study on the 2-10keV selected sample comprising 97 sources to the limit 8x10^-16^erg/s/cm^2^, this being the most complete in terms of optical identification rate (86 per cent) and redshift determination fraction (63 per cent; both spectroscopic and photometric).
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/887/20
- Title:
- Deep Chandra survey of the SMC. III. HMXBs
- Short Name:
- J/ApJ/887/20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have compiled the most complete census of high-mass X-ray binaries (HMXBs) in the Small Magellanic Cloud with the aim to investigate the formation efficiency of young accreting binaries in its low-metallicity environment. In total, we use 123 X-ray sources with detections in our Chandra X-ray Visionary Program (XVP), supplemented by 14 additional (likely and confirmed) HMXBs identified by Haberl & Sturm (2016, J/A+A/586/A81) that fall within the XVP area, but are neither detected in our survey (nine sources) nor matched with any of the 127 sources identified in the XVP data (five sources). Specifically, we examine the number ratio of the HMXBs [N(HMXBs)] to (a) the number of OB stars, (b) the local star formation rate (SFR), and (c) the stellar mass produced during the specific star formation burst, all as a function of the age of their parent stellar populations. Each of these indicators serves a different role, but in all cases we find that the HMXB formation efficiency increases as a function of time (following a burst of star formation) up to ~40-60Myr, and then gradually decreases. The formation efficiency peaks at ~30-40Myr with average rates of N(HMXB)/SFR=339_-83_^+78^(M_{sun}_/yr)^-1^, and N(HMXB)/M*=(8.74_-0.92_^+1.0^)x10^-6^M_{sun}_^-1^, in good agreement with previous estimates of the average formation efficiency in the broad ~20-60Myr age range.
- ID:
- ivo://CDS.VizieR/J/ApJ/758/135
- Title:
- DEEP2 galaxies with UV spectra in the EGS
- Short Name:
- J/ApJ/758/135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate galactic-scale outflowing winds in 72 star-forming galaxies at z~1 in the Extended Groth Strip. Galaxies were selected from the DEEP2 survey and follow-up LRIS spectroscopy was obtained covering Si II, C IV, Fe II, Mg II, and Mg I lines in the rest-frame ultraviolet. Using Galaxy Evolution Explorer (GALEX), Hubble Space Telescope (HST), and Spitzer imaging available for the Extended Groth Strip, we examine galaxies on a per-object basis in order to better understand both the prevalence of galactic outflows at z~1 and the star-forming and structural properties of objects experiencing outflows. Gas velocities, measured from the centroids of Fe II interstellar absorption lines, are found to span the interval [-217,+155]km/s. We find that ~40% (10%) of the sample exhibits blueshifted Fe II lines at the 1{sigma} (3{sigma}) level. We also measure maximal outflow velocities using the profiles of the Fe II and Mg II lines; we find that Mg II frequently traces higher velocity gas than Fe II. Using quantitative morphological parameters derived from the HST imaging, we find that mergers are not a prerequisite for driving outflows. More face-on galaxies also show stronger winds than highly inclined systems, consistent with the canonical picture of winds emanating perpendicular to galactic disks. In light of clumpy galaxy morphologies, we develop a new physically motivated technique for estimating areas corresponding to star formation. We use these area measurements in tandem with GALEX-derived star formation rates (SFRs) to calculate SFR surface densities. At least 70% of the sample exceeds an SFR surface density of 0.1M_{sun}_/yr/kpc2, the threshold necessary for driving an outflow in local starbursts. At the same time, the outflow detection fraction of only 40% in Fe II absorption provides further evidence for an outflow geometry that is not spherically symmetric. We see a ~3{sigma} trend between outflow velocity and SFR surface density, but no significant trend between outflow velocity and SFR. Higher resolution data are needed in order to test the scaling relations between outflow velocity and both SFR and SFR surface density predicted by theory.
- ID:
- ivo://CDS.VizieR/J/ApJS/193/14
- Title:
- DEEP3 Galaxy Redshift Survey: GOODS-N field
- Short Name:
- J/ApJS/193/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of spectroscopic observations in the GOODS-N field completed using DEIMOS on the Keck II telescope as part of the DEEP3 Galaxy Redshift Survey (M. C. Cooper et al. 2011, in preparation). Observations of 370 unique targets down to a limiting magnitude of R_AB_=24.4 yielded 156 secure redshifts. In addition to redshift information, we provide sky-subtracted one- and two-dimensional spectra of each target. Observations were conducted following the procedures of the Team Keck Redshift Survey (TKRS, Cat. J/AJ/127/3121), thereby producing spectra that augment the TKRS sample while maintaining the uniformity of its spectral database.
- ID:
- ivo://CDS.VizieR/J/ApJ/654/115
- Title:
- DEEP2 Galaxy Redshift Survey: SDSS QSOs
- Short Name:
- J/ApJ/654/115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the clustering of Deep Extragalactic Evolutionary Probe 2 (DEEP2) galaxies at 0.7<z<1.4 around quasars identified using both the Sloan Digital Sky Survey (SDSS) and DEEP2 surveys. We measure the two-point cross-correlation of a sample of 36 optically selected, spectroscopically identified quasars from the SDSS and 16 more found in the DEEP2 survey with the full DEEP2 galaxy sample over scales 0.1h^-1^MPc<r_p_<10h^-1^Mpc.
- ID:
- ivo://CDS.VizieR/J/MNRAS/404/1005
- Title:
- Deep 15GHz survey (9C continued)
- Short Name:
- J/MNRAS/404/1005
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 9C survey of radio sources with the Ryle Telescope at 15.2GHz was set up to survey the fields of the cosmic microwave background telescope, the Very Small Array. In our first paper we described three regions of the survey, constituting a total area of to a completeness limit of ~25mJy. Here we present results from series of deeper regions, amounting to an area of 115deg^2^ complete to ~10mJy and of 29deg^2^ complete to ~5.5mJy. The compound source catalogue contains a total of 643 sources.
- ID:
- ivo://CDS.VizieR/J/MNRAS/439/1212
- Title:
- Deep 20GHz survey of CDFS and SDSS Stripe 82
- Short Name:
- J/MNRAS/439/1212
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a source catalogue and first results from a deep, blind radio survey carried out at 20GHz with the Australia Telescope Compact Array, with follow-up observations at 5.5, 9 and 18GHz. The Australia Telescope 20GHz (AT20G) deep pilot survey covers a total area of 5deg^2^ in the Chandra Deep Field South and in Stripe 82 of the Sloan Digital Sky Survey. We estimate the survey to be 90% complete above 2.5mJy. Of the 85 sources detected, 55percent have steep spectra ({alpha}_1.4_^20^<-0.5) and 45% have flat or inverted spectra ({alpha}_1.4_^20^>=-0.5). The steep-spectrum sources tend to have single power-law spectra between 1.4 and 18GHz, while the spectral indices of the flat- or inverted-spectrum sources tend to steepen with frequency. Among the 18 inverted-spectrum ({alpha}_1.4_^20^>=0.0) sources, 10 have clearly defined peaks in their spectra with {alpha}_1.4_^5.5^>0.15 and {alpha}_9_^18^<-0.15. On a 3-yr time-scale, at least 10 sources varied by more than 15percent at 20GHz, showing that variability is still common at the low flux densities probed by the AT20G-deep pilot survey.
- ID:
- ivo://CDS.VizieR/J/ApJS/150/417
- Title:
- Deep, high-resolution survey at 74MHz
- Short Name:
- J/ApJS/150/417
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a 74MHz survey of a 165deg^2^ region located near the north Galactic pole. This survey has an unprecedented combination of both resolution (25" FWHM) and sensitivity ({sigma} as low as 24mJy/beam). We detect 949 sources at the 5{sigma} level in this region, enough to begin exploring the nature of the 74MHz source population. We present differential source counts, spectral index measurements, and the size distribution as determined from counterparts in the high-resolution FIRST 1.4GHz survey, Cat. <VIII/71>.
- ID:
- ivo://CDS.VizieR/J/ApJ/743/64
- Title:
- Deep infrared photometry of {sigma} Ori cluster
- Short Name:
- J/ApJ/743/64
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a deep I, Z photometric survey covering a total area of 1.12deg^2^ of the {sigma} Orionis cluster and reaching completeness magnitudes of I=22 and Z=21.5mag. From I, I-Z color-magnitude diagrams we have selected 153 candidates that fit the previously known sequence of the cluster. They have magnitudes in the range I=16-23mag, which corresponds to a mass interval from 0.1 down to 0.008M_{sun}_ at the most probable age of {sigma} Orionis (2-4Myr). Using J-band photometry, we find that 124 of the 151 candidates within the completeness of the optical survey (82%) follow the previously known infrared photometric sequence of the cluster and are probably members. We have studied the spatial distribution of the very low mass stars and brown dwarf population of the cluster and found that there are objects located at distances greater than 30 arcmin to the north and west of {sigma} Orionis that probably belong to different populations of the Orion's Belt. For the 102 bona fide {sigma} Orionis cluster member candidates, we find that the radial surface density can be represented by a decreasing exponential function ({sigma}={sigma}_0_e^-r/r_0_^) with a central density of {sigma}_0_=0.23+/-0.03 objects arcmin^-2^ and a characteristic radius of r_0_=9.5+/-0.7 arcmin. Using near-infrared JHK-band data from Two Micron All Sky Survey and UKIRT Deep Infrared Sky Survey and mid-infrared data from Infrared Array Camera/Spitzer, we find that about 5%-9% of the brown dwarf candidates in the {sigma} Orionis cluster have K-band excesses and 30%+/-7% of them show mid-infrared excesses at wavelengths longer than 5.8um. These are probably related to the presence of disks, most of which are "transition disks".
- ID:
- ivo://CDS.VizieR/J/MNRAS/383/75
- Title:
- Deep 610MHz survey of ELAIS-N1 sources
- Short Name:
- J/MNRAS/383/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of the ELAIS-N1 field taken at 610MHz with the Giant Metrewave Radio Telescope are presented. Nineteen pointings were observed, covering a total area of 9 square degrees with a resolution of 6x5arcsec^2^, PA=45deg. Four of the pointings were deep observations with an rms of ~40uJy before primary beam correction, with the remaining fifteen pointings having an rms of ~70uJy. The techniques used for data reduction and production of a mosaicked image of the region are described, and the final mosaic, along with a catalogue of 2500 sources detected above 6{sigma}, are presented. This work complements the large amount of optical and infrared data already available on the region. For further details of the surveys and data analysis procedures please refer to the published paper.
