- ID:
- ivo://CDS.VizieR/J/ApJ/670/1367
- Title:
- Gemini Deep Planet Survey
- Short Name:
- J/ApJ/670/1367
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the Gemini Deep Planet Survey, a near-infrared adaptive optics search for giant planets and brown dwarfs around 85 nearby young stars. The observations were obtained with the Altair adaptive optics system at the Gemini North telescope, and angular differential imaging was used to suppress the speckle noise of the central star. Typically, the observations are sensitive to angular separations beyond 0.5" with 5{sigma} contrast sensitivities in magnitude difference at 1.6um of 9.5 at 0.5", 12.9 at 1", 15.0 at 2", and 16.5 at 5". These sensitivities are sufficient to detect planets more massive than 2M_{Jup}_ with a projected separation in the range 40-200AU around a typical target. Second-epoch observations of 48 stars with candidates (out of 54) have confirmed that all candidates are unrelated background stars. A detailed statistical analysis of the survey results is presented.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/873/35
- Title:
- Gemini GNIRS NIR spectroscopy of 50 QSOs at z>~5.7
- Short Name:
- J/ApJ/873/35
- Date:
- 19 Jan 2022 09:09:09
- Publisher:
- CDS
- Description:
- We report initial results from a large Gemini program to observe z>~5.7 quasars with GNIRS near-IR spectroscopy. Our sample includes 50 quasars with simultaneous ~0.85-2.5{mu}m spectra covering the rest-frame ultraviolet and major broad emission lines from Ly{alpha} to MgII. We present spectral measurements for these quasars and compare with their lower redshift counterparts at z=1.5-2.3. We find that when quasar luminosity is matched, there are no significant differences between the rest-UV spectra of z>~5.7 quasars and the low-z comparison sample. High-z quasars have similar continuum and emission line properties and occupy the same region in the black hole mass and luminosity space as the comparison sample, accreting at an average Eddington ratio of ~0.3. There is no evidence for super-Eddington accretion or hypermassive (>10^10^M_{sun}_) black holes within our sample. We find a mild excess of quasars with weak CIV lines relative to the control sample. Our results, corroborating earlier studies but with better statistics, demonstrate that these high-z quasars are already mature systems of accreting supermassive black holes operating with the same physical mechanisms as those at lower redshifts.
- ID:
- ivo://CDS.VizieR/J/ApJS/174/136
- Title:
- GEMS survey data and catalog
- Short Name:
- J/ApJS/174/136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the data reduction and object cataloging for the GEMS survey, a large-area (800 arcmin^2^) two-band (F606W and F850LP) imaging survey with the Advanced Camera for Surveys on the Hubble Space Telescope, centered on the Chandra Deep Field-South.
- ID:
- ivo://CDS.VizieR/J/A+A/601/A112
- Title:
- GES iDR4 Mg-Al anticorrelation in GCs
- Short Name:
- J/A+A/601/A112
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use Gaia-ESO Survey iDR4 data to explore the Mg-Al anti-correlation in globular clusters, that were observed as calibrators, as a demonstration of the quality of Gaia-ESO Survey data and analysis. The results compare well with the available literature, within 0.1~[-] or less, after a small (compared to the Minternal spreads) offset between the UVES and the GIRAFFE data of 0.10-0.15dex was taken into account. In particular, we present for the first time data for NGC 5927, one of the most metal-rich globular clusters studied in the literature so far with [Fe/H]=-0.49dex, that was included to connect with the open cluster regime in the Gaia-ESO Survey internal calibration. The extent and shape of the Mg-Al anti-correlation provide strong constraints on the multiple population phenomenon in globular clusters. In particular, we studied the dependency of the Mg-Al anti-correlation extension with metallicity, present-day mass, and age of the clusters, using GES data in combination with a large set of homogenized literature measurements. We find a dependency with both metallicity and mass, that is evident when fitting for the two parameters simultaneously, but no significant dependency with age. We confirm that the Mg-Al anti-correlation is not seen in all clusters, but disappears for the less massive or most metal-rich ones. We also use our dataset to see whether a normal anti-correlation would explain the low [Mg/{alpha}] observed in some extragalactic globular clusters, but find that none of the clusters in our sample can reproduce it, and more extreme chemical compositions (like the one of NGC 2419) would be required. We conclude that GES iDR4 data already meet the requirements set by the main survey goals, and can be used to study in detail globular clusters even if the analysis procedures were not specifically designed for them.
- ID:
- ivo://CDS.VizieR/J/ApJ/731/100
- Title:
- 148GHz ACT extragalactic sources catalog
- Short Name:
- J/ApJ/731/100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on extragalactic sources detected in a 455deg^2^ map of the southern sky made with data at a frequency of 148GHz from the Atacama Cosmology Telescope (ACT) 2008 observing season. We provide a catalog of 157 sources with flux densities spanning two orders of magnitude: from 15mJy to 1500mJy. Comparison to other catalogs shows that 98% of the ACT detections correspond to sources detected at lower radio frequencies. Three of the sources appear to be associated with the brightest cluster galaxies of low-redshift X-ray-selected galaxy clusters. Estimates of the radio to millimeter-wave spectral indices and differential counts of the sources further bolster the hypothesis that they are nearly all radio sources, and that their emission is not dominated by re-emission from warm dust. In a bright (>50mJy) 148GHz selected sample with complete cross-identifications from the Australia Telescope 20GHz survey, we observe an average steepening of the spectra between 5, 20, and 148GHz with median spectral indices of {alpha}_5-20_=-0.07+/-0.06, {alpha}_20-148_=-0.39+/-0.04, and {alpha}_5-148_=-0.20+/-0.03. When the measured spectral indices are taken into account, the 148GHz differential source counts are consistent with previous measurements at 30GHz in the context of a source count model dominated by radio sources. Extrapolating with an appropriately rescaled model for the radio source counts, the Poisson contribution to the spatial power spectrum from synchrotron-dominated sources with flux density less than 20mJy is C^Sync^=(2.8+/-0.3)x10^-6^{mu}K^2^.
- ID:
- ivo://CDS.VizieR/J/ApJ/742/27
- Title:
- 15GHz and jet properties of MOJAVE blazars
- Short Name:
- J/ApJ/742/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the Fermi Large Area Telescope {gamma}-ray and 15GHz Very Long Baseline Array radio properties of a joint {gamma}-ray and radio-selected sample of active galactic nuclei (AGNs) obtained during the first 11 months of the Fermi mission (2008 August 4-2009 July 5). Our sample contains the brightest 173 AGNs in these bands above declination -30{deg} during this period, and thus probes the full range of {gamma}-ray loudness ({gamma}-ray to radio band luminosity ratio) in the bright blazar population. The latter quantity spans at least 4 orders of magnitude, reflecting a wide range of spectral energy distribution (SED) parameters in the bright blazar population. The BL Lac objects, however, display a linear correlation of increasing {gamma}-ray loudness with synchrotron SED peak frequency, suggesting a universal SED shape for objects of this class.
- ID:
- ivo://CDS.VizieR/J/ApJS/200/5
- Title:
- 95GHz class I methanol maser survey
- Short Name:
- J/ApJS/200/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report a survey with the Purple Mountain Observatory 13.7m radio telescope for class I methanol masers from the 95GHz (8_0_-7_1_A^+^) transition. Two hundred and fourteen target sources were selected by combining information from both the Spitzer GLIMPSE and 1.1mm Bolocam Galactic Plane Survey (BGPS) catalogs. The observed sources satisfy the GLIMPSE mid-IR criteria of [3.6]-[4.5]>1.3, [3.6]-[5.8]>2.5, [3.6]-[8.0]>2.5 and 8.0um mag less than 10; they also have an associated 1.1mm BGPS source. Class I methanol maser emission was detected in 63 sources, corresponding to a detection rate of 29% for this survey. For the majority of detections (43), this is the first identification of class I methanol masers associated with these sources. We show that the intensity of the class I methanol maser emission is not closely related to mid-IR intensity or the colors of the GLIMPSE point sources; however, it is closely correlated with properties (mass and beam-averaged column density) of the BGPS sources. Comparison of measures of star formation activity for the BGPS sources with and without class I methanol masers indicates that the sources with class I methanol masers usually have higher column density and larger flux density than those without them.
- ID:
- ivo://CDS.VizieR/J/ApJ/488/224
- Title:
- 4.85 GHz fluxes of H II regions
- Short Name:
- J/ApJ/488/224
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an all-sky flux catalog of 760 H II regions with angular sizes ranging up to 10' at 4.85GHz. The data were compiled in a self-consistent manner from existing images of the Green Bank and Parkes-MIT-NRAO 4.85GHz radio continuum surveys. Nearly 35% of these H II regions have fluxes measured from these surveys for the first time. We compared our results to the previously published source catalogs which fit the same data. The new flux measurements agree within 5%-7% of these values and fall well within the formal errors. The diameters fall within 16% of the previously published fits to the same data, within the formal uncertainties of these values.
- ID:
- ivo://CDS.VizieR/J/AJ/123/1784
- Title:
- 1.4 GHz imaging of the Bootes field
- Short Name:
- J/AJ/123/1784
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from our deep (16x12hr) Westerbork Synthesis Radio Telescope (WSRT) observations of the approximately 7{deg}^2^ Bootes Deep Field, centered at 14h 32min 05.75s, 34{deg} 16' 47.5" (J2000.0). Our survey consists of 42 discrete pointings, with enough overlap to ensure a uniform sensitivity across the entire field, with a limiting sensitivity of 28{mu}Jy (1{sigma}_rms_). The catalog contains 3172 distinct sources, of which 316 are resolved by the 13"x27" beam. The Bootes field is part of the optical/near-infrared imaging and spectroscopy survey effort conducted at various institutions. The combination of these data sets and the deep nature of the radio observations will allow unique studies of a large range of topics including the redshift evolution of the luminosity function of radio sources, the K-z relation, the clustering environment of radio galaxies, the radio/far-infrared correlation for distant starbursts, and the nature of obscured radio-loud active galactic nuclei. The observations were carried out by the WSRT operating at 1.380GHz. The WSRT consists of 14 25m-telescopes arranged in a 2.7km east-west configuration. As the back end, we used the digital continuum back end with eight subbands of 10MHz bandwidth each. The smallest baseline (9-A) was set to 54m to limit shadowing at the expense of a reduction in large spatial structure sensitivity (~800" for this minimum baseline and frequency).
- ID:
- ivo://CDS.VizieR/VIII/96
- Title:
- 6-GHz methanol multibeam maser catalogue
- Short Name:
- VIII/96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a Galactic plane survey of methanol masers at 6668 MHz using a seven-beam receiver on the Parkes telescope, refered to as MX observations. Paper I provides sensitive unbiased coverage of a large region around the Galactic Centre. Details are given for 183 methanol maser sites in the longitude range 345{deg} through the Galactic Centre to 6{deg}. Within 6{deg} of the Galactic Centre, we found 88 maser sites, of which more than half (48) are new discoveries. The masers are confined to a narrow Galactic latitude range, indicative of many sources at the Galactic Centre distance and beyond, and confined to a thin disc population; there is no high-latitude population that might be ascribed to the Galactic bulge. Paper II spans the longitude range 6{deg} to 20{deg}. We report the detection of 119 maser sources, of which 42 are new discoveries. Paper III covers the longitude range 330{deg}-345{deg}, yielding 198 masers, of which more than 40 per cent are new discoveries. Paper IV span the longitude range 186{deg}-330{deg}. We report 207 maser detections, 89 new to the survey. This completes the southern sky part of the methanol multibeam survey and includes a large proportion of new sources, 43 per cent. We also include results from blind observations of the Orion-Monoceros star-forming region, formally outside the latitude range of the methanol multibeam survey; only the four previously known methanol emitting sites were detected, of which we present new positions and spectra for masers at Orion A (south) and Orion B, obtained with the Multi-Element Radio Linked Interferometer Network (MERLIN) array.
