- ID:
- ivo://CDS.VizieR/J/MNRAS/501/4550
- Title:
- The complete Arecibo Ultra-Deep Survey
- Short Name:
- J/MNRAS/501/4550
- Date:
- 23 Feb 2022 08:32:49
- Publisher:
- CDS
- Description:
- The Arecibo Ultra-Deep Survey (AUDS) is a blind HI survey aimed at detecting galaxies beyond the local Universe in the 21-cm emission line of neutral hydrogen (HI). The Arecibo L-band Feed Array (ALFA) was used to image an area of 1.35deg^2^ to a redshift depth of 0.16, using a total on-source integration time of over 700h. The long integration time and small observation area makes it one of the most sensitive HI surveys, with a noise level of ~75{mu}Jy per 21.4kHz (equivalent to 4.5km/s at redshift z=0). We detect 247 galaxies in the survey, more than doubling the number already detected in AUDS60. The mass range of detected galaxies is log(M_HI_[h_70_^-2^M_{sun}_])=6.32-10.76. A modified maximum likelihood method is employed to construct an H I mass function (HIMF). The best fitting Schechter parameters are low-mass slope {alpha}=-1.37+/-0.05, characteristic mass log(M^*^[h_70_^-2^M_{sun}_])=10.15+/-0.09, and density {Phi}_*_=(2.41+/-0.57)x10^-3^h_70_^3^Mpc^-3^/dex. The sample was divided into low- and high-redshift bins to investigate the evolution of the HIMF. No change in low-mass slope {alpha} was measured, but an increased characteristic mass M*, was noted in the higher redshift sample. Using Sloan Digital Sky Survey data to define relative galaxy number density, the dependence of the HIMF with environment was also investigated in the two AUDS regions. We find no significant variation in {alpha} or M*. In the surveyed region, we measured a cosmic HI density {Omega}_HI_=(3.55+/-0.30)x10^-4^h_70_^-1^. There appears to be no evolutionary trend in {Omega}_HI_ above 2{sigma} significance between redshifts of 0 and 0.16.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/356/590
- Title:
- The CORALIE survey for extrasolar planets II
- Short Name:
- J/A+A/356/590
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Here we list the CORALIE radial-velocity measurements for HD 75289 and HD 130322. CORALIE is a fiber-fed echelle spectrograph designed for high-precision radial-velocity measurements. It is mounted on the 1.2-m "Leonard Euler" Swiss Telescope at ESO-La Silla Observatory (Chile).
- ID:
- ivo://CDS.VizieR/J/A+A/392/215
- Title:
- The CORALIE survey for extrasolar planets. IX.
- Short Name:
- J/A+A/392/215
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table 1 contains the CORALIE radial-velocity measurements for the stellar system HD41004. CORALIE is a fiber-fed echelle spectrograph designed for high-precision radial-velocity measurements. It is mounted on the 1.2-m "Leonard Euler" Swiss Telescope at ESO-La Silla Observatory (Chile).
- ID:
- ivo://CDS.VizieR/J/A+A/375/205
- Title:
- The CORALIE survey for extrasolar planets V
- Short Name:
- J/A+A/375/205
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table 1-6 contain the CORALIE radial-velocity measurements for the 6 Solar-type stars hosting planetary companions: GJ 3021 (HD 1237), HD 52265, HD 169830, iota Hor (HD 17051), HD 210277 and HD 217107. CORALIE is a fiber-fed echelle spectrograph designed for high-precision radial-velocity measurements. It is mounted on the 1.2-m "Leonard Euler" Swiss Telescope at ESO-La Silla Observatory (Chile).
- ID:
- ivo://CDS.VizieR/J/A+A/390/267
- Title:
- The CORALIE survey for extrasolar planets VIII
- Short Name:
- J/A+A/390/267
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Doppler CORALIE measurements of the solar-type stars HD 141937, HD 162020, HD 168443 and HD 202206 show Keplerian radial-velocity variations revealing the presence of 4 new companions with minimum masses close to the planet/brown-dwarf transition, namely with m_2_sini=9.7, 14.4, 16.9, and 17.5M_Jup_, respectively. The orbits present fairly large eccentricities (0.22<=e<=0.43). Except for HD 162020 , the parent stars are metal rich compared to the Sun, as are most of the detected extra-solar planet hosts. Considerations of tidal dissipation in the short-period HD 162020 system points towards a brown-dwarf nature for the low-mass companion. HD 168443 is a multiple system with two low-mass companions being either brown dwarfs or formed simultaneously in the protoplanetary disks as superplanets. For HD 202206, the radial velocities show an additional drift revealing a further outer companion, the nature of which is still unknown. Finally, the stellar-host and orbital properties of massive planets are examined in comparison to lighter exoplanets. Observed trends include the need of metal-rich stars to form massive exoplanets and the lack of short periods for massive planets. If confirmed with improved statistics, these features may provide constraints for the migration scenario.
- ID:
- ivo://CDS.VizieR/J/A+A/415/391
- Title:
- The CORALIE survey for extrasolar planets. XII
- Short Name:
- J/A+A/415/391
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The paper summarizes the information gathered for 16 exoplanet candidates discovered with the CORALIE echelle spectrograph mounted on the Euler Swiss telescope at La Silla Observatory. Here we give individual velocity measurements for the 13 stars harbouring a single planet companion. The data for the multi-planet systems will be published later.
18757. The Core of NGC 6624
- ID:
- ivo://CDS.VizieR/J/AJ/109/639
- Title:
- The Core of NGC 6624
- Short Name:
- J/AJ/109/639
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used the Faint Object Camera on the Hubble Space Telescope (HST) to observe three fields near the center of the post-collapse globular cluster NGC 6624 in B and V. We use individual stellar positions and a maximum-likelihood technique to measure a position for the cluster center. We then transfer this position and the position of the x-ray source 4U 1820-30 to right ascension and declination, and correct an error of 1.8" in an earlier paper. From star counts, we obtain a density profile, with a power-law cusp of slope -0.84 +/- 0.16. No flat core is evident. We construct color-magnitude diagrams down to the main-sequence turnoff near the cluster center, and more than three magnitudes below the turnoff in the outermost field at r=28". The former diagram reveals a central population of blue stragglers, which has not previously been observed in this cluster. These blue stragglers are quite similar in specific frequency to those recently observed by HST in the core of 47 Tuc, and their presence adds to the growing evidence of stellar interactions in dense globular-cluster cores.
- ID:
- ivo://CDS.VizieR/J/ApJ/872/81
- Title:
- The COS CGM Compendium (CCC). II. Lyman limit syst.
- Short Name:
- J/ApJ/872/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from our COS circumgalactic medium (CGM) compendium (CCC), a survey of the CGM at z<~1 using HI-selected absorbers with 15<logN_HI_<19. We focus here on 82 partial Lyman limit systems (pLLSs, 16.2<=logN_HI_<17.2) and 29 LLSs (17.2<=logN_HI_<19). Using Bayesian techniques and Markov Chain Monte Carlo sampling of a grid of photoionization models, we derive the posterior probability distribution functions (PDFs) for the metallicity of each absorber in CCC. We show that the combined pLLS metallicity PDF at z<~1 has two main peaks at [X/H]~-1.7 and -0.4, with a strong dip at [X/H]~-1. The metallicity PDF of the LLSs might be more complicated than a unimodal or bimodal distribution. The pLLSs and LLSs probe a similar range of metallicities -3<~[X/H]<~+0.4, but the fraction of very metal-poor absorbers with [X/H]<~-1.4 is much larger for the pLLSs than the LLSs. In contrast, absorbers with logN_HI_>=19 have mostly -1<~[X/H]<~0 at z<~1. The metal-enriched gas probed by pLLSs and LLSs confirms that galaxies that have been enriching their CGM over billions of years. Surprisingly, despite this enrichment, there is also abundant metal-poor CGM gas (41%-59% of the pLLSs have [X/H]<~-1.4), representing a reservoir of near-pristine gas around z<~1 galaxies. We compare our empirical results to recent cosmological zoom simulations, finding some discrepancies, including an overabundance of metal- enriched CGM gas in simulations.
- ID:
- ivo://CDS.VizieR/J/ApJ/866/33
- Title:
- The COS CGM compendium. I. Initial results
- Short Name:
- J/ApJ/866/33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a neutral hydrogen-selected absorption-line survey of gas with HI column densities 15<logN_HI_<19 at z<~1 using the Cosmic Origins Spectrograph on the Hubble Space Telescope. Our main aim is to determine the metallicity distribution of these absorbers. Our sample consists of 224 absorbers selected on the basis of their HI absorption strength. Here we discuss the properties of our survey and the immediate empirical results. We find singly and doubly ionized metal species, and HI typically have similar velocity profiles, implying they probe gas in the same or similar environments. The ionic ratios (e.g., N_CII_/N_CIII_, N_OI_/N_CII_) indicate that the gas in these absorbers is largely ionized, and the ionization conditions are quite comparable across the sampled N_HI_ range. The Doppler parameters of the HI imply T<~5x10^4^K on average, consistent with the gas being photoionized. The MgII column densities span >2 orders of magnitude at any given N_HI_, indicating a wide range of metallicities (from solar to <1/100 solar). In the range of 16.2<~logN_HI_<~17, there is a gap in the N_MgII_ distribution corresponding to gas with ~10% solar metallicity, consistent with the gap seen in the previously identified bimodal metallicity distribution in this column density regime. Less than 3% of the absorbers in our sample show no detectable metal absorption, implying that truly pristine gas at z<~1 is uncommon. We find <[FeII/MgII]>=-0.4+/-0.3, and since {alpha}-enhancement can affect this ratio, dust depletion is extremely mild.
- ID:
- ivo://CDS.VizieR/J/ApJ/818/187
- Title:
- The cosmic TeV gamma-ray background spectrum
- Short Name:
- J/ApJ/818/187
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Fermi gamma-ray space telescope has revolutionized our understanding of the cosmic gamma-ray background radiation in the GeV band. However, investigation on the cosmic TeV gamma-ray background radiation still remains sparse. Here, we report the lower bound on the cosmic TeV gamma-ray background spectrum placed by the cumulative flux of individual detected extragalactic TeV sources including blazars, radio galaxies, and starburst galaxies. The current limit on the cosmic TeV gamma-ray background above 0.1TeV is obtained as 2.8x10^-8^(E/100GeV)^-0.55^exp(-E/2100GeV)[GeV/cm2/s/sr] <E^2^dN/dE<1.1x10^-7^(E/100GeV)^-0.49^[GeV/cm2/s/sr], where the upper bound is set by requirement that the cascade flux from the cosmic TeV gamma-ray background radiation can not exceed the measured cosmic GeV gamma-ray background spectrum. Two nearby blazars, Mrk421 and Mrk501, explain ~70% of the cumulative background flux at 0.8-4TeV, while extreme blazars start to dominate at higher energies. We also provide the cumulative background flux from each population, i.e., blazars, radio galaxies, and starburst galaxies which will be the minimum requirement for their contribution to the cosmic TeV gamma-ray background radiation.