- ID:
- ivo://CDS.VizieR/J/AJ/131/2859
- Title:
- Extragalactic First Look Survey: 24{mu}m data
- Short Name:
- J/AJ/131/2859
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the reduction of the 24{mu}m data obtained during the first cosmological survey performed by the Spitzer Space Telescope. Images of a region of sky at moderately high Galactic latitude (l=88.3{deg}, b=+34.9{deg}) were obtained on 2003 December 9-11. The survey consists of a shallow observation of 2.5x2{deg}^2^ centered at 17:18 +59:30 (main survey) and a deeper observation of 1{deg}x0.5{deg} centered at 17:17 +59:45 (verification survey). Issues with the reduction of the 24{mu}m MIPS data are discussed and solutions to attenuate instrumental effects are proposed and applied to the data. Approximately 17000 sources are extracted with a signal-to-noise ratio (S/N) greater than 5. The photometry of the point sources is evaluated through point-spread function (PSF) fitting using an empirical PSF derived from the data. Aperture corrections and the absolute calibration have been checked using stars in the field. Astrometric and photometric errors depend on the S/N of the source varying between 0.35"-1" and 5%-15%, respectively, for sources detected at 20-5{sigma}. The fluxes of the 123 extended sources have been estimated through aperture photometry. The extended sources cover less than 0.3% of the total area of the survey. Based on simulations, the main and verification surveys are 50% complete at 0.3 and 0.15mJy, respectively. Counterparts have been searched for in optical and radio catalogs.
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- ID:
- ivo://CDS.VizieR/VII/287
- Title:
- Extragalactic linear polarization meas. agglomeration
- Short Name:
- VII/287
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- In the framework of the Standard Model Extension (SME), we present improved constraints on anisotropic Lorentz invariance and Charge-Parity-Time (CPT) violation by searching for astrophysical signals of cosmic vacuum birefringence with broadband optical polarimetry of high redshift astronomical sources, including Active Galactic Nuclei and Gamma-Ray Burst afterglows. We generalize Kislat (Constraints on lorentz invariance violation from optical polarimetry of astrophysical objects. Symmetry, 10(11), 2018. ISSN 2073-8994. doi:10.3390/sym10110596), which studied the SME mass dimension d=4 case, to arbitrary mass dimension for both the CPT-even and CPT-odd cases. We then present constraints on all 10, 16, and 42 anisotropic birefringent SME coefficients for dimension d=4, d=5, and d=6 models respectively, using 7554 observations for odd d and 7376 observations for even d of 1278 unique sources on the sky, which, to our knowledge comprises the most complete catalog of optical polarization from extragalactic sources in the literature to date. Compared to the smaller sample of 44 and 45 broadband optical polarimetry observations analyzed in Kislat (Constraints on lorentz invariance violation from optical polarimetry of astrophysical objects. Symmetry, 10(11), 2018. ISSN 2073-8994. doi:10.3390/sym10110596) and Kislat et al. (2017 Phys. Rev. D, 95(8):083013, doi: 10.1103/PhysRevD.95.083013), our dimension d=4 and d=5 average constraints are more sensitive by factors of 35 and 10, corresponding to a reduction in allowed SME parameter space volume for these studies of 15 and 16 orders of magnitude, respectively. Constraints from individual lines of sight can be significantly stronger using spectropolarimetry, due to the steep energy dependence of birefringence effects at increasing mass dimension. Nevertheless, due to the increased number of observations and lines of sight in our catalog, our average d=4 and d=5 broadband constraints are within factors of 2 and 12 of previous constraints using spectropolarimetry from Kislat (Constraints on lorentz invariance violation from optical polarimetry of astrophysical objects. Symmetry, 10(11), 2018. ISSN 2073-8994. doi:10.3390/sym10110596) and Kislat et al. (2017, Phys. Rev. D 95(8):083013, doi: 10.1103/PhysRevD.95.083013), respectively, using an independent data set and an improved analysis method. By contrast, our anisotropic constraints on all 42 birefringent SME coefficients for d=6 are the first to be presented in the literature.
- ID:
- ivo://CDS.VizieR/J/ApJ/801/143
- Title:
- Extrasolar Kuiper belts from Herschel
- Short Name:
- J/ApJ/801/143
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The study of the planet-debris disk connection can shed light on the formation and evolution of planetary systems and may help "predict" the presence of planets around stars with certain disk characteristics. In preliminary analyses of subsamples of the Herschel DEBRIS and DUNES surveys, Wyatt et al. (2012MNRAS.424.1206W) and Marshall et al. (2014A&A...565A..15M) identified a tentative correlation between debris and the presence of low-mass planets. Here we use the cleanest possible sample out of these Herschel surveys to assess the presence of such a correlation, discarding stars without known ages, with ages <1Gyr, and with binary companions <100AU to rule out possible correlations due to effects other than planet presence. In our resulting subsample of 204 FGK stars, we do not find evidence that debris disks are more common or more dusty around stars harboring high-mass or low-mass planets compared to a control sample without identified planets.
- ID:
- ivo://CDS.VizieR/J/A+A/649/L8
- Title:
- Extreme adaptive optics astrometry of R136
- Short Name:
- J/A+A/649/L8
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We compared high-contrast near-infrared images of the core of R136 taken by VLT/SPHERE, in two epochs separated by 3.06 years. For the first time we monitored the dynamics of the detected sources in the core of R136 from a ground-based telescope with adaptive optics. The aim of these observations was to search for High prOper Motion cAndidates (HOMAs) in the central region of R136 (r<6") where it has been challenging for other instruments. Two bright sources (K<15mag and V<16mag) are located near R136a1 and R136c (massive WR stars) and have been identified as potential HOMAs. These sources have significantly shifted in the images with respect to the mean shift of all reliable detected sources and their neighbours, and six times their own astrometric errors. We calculate their proper motions to be 1.36+/-0.22mas/yr^2^ (321+/-52km/s) and 1.15+/-0.11mas/yr^2^ (273+/-26km/s). We discuss different possible scenarios to explain the magnitude of such extreme proper motions, and argue for the necessity to conduct future observations to conclude on the nature of HOMAs in the core of R136.
- ID:
- ivo://CDS.VizieR/J/MNRAS/469/347
- Title:
- Extremely Isolated Galaxies. II.
- Short Name:
- J/MNRAS/469/347
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have selected a sample of 41 extremely isolated galaxies (EIGs) from the local Universe using both optical and HI Arecibo Legacy Fast ALFA survey redshifts. Narrow-band H{alpha} and wide-band imaging along with public data were used to derive star formation rates (SFRs), star formation histories and morphological classifications for the EIGs. We have found that the extreme isolation of the EIGs does not affect considerably their star formation compared to field galaxies. EIGs are typically 'blue cloud' galaxies that fit the 'main sequence of star-forming galaxies' and may show asymmetric star formation and strong compact star-forming regions. We discovered surprising environmental dependences of the HI content, M_HI_, and of the morphological type of EIGs; the most isolated galaxies (of subsample EIG-1) have lower M_HI_ on average (with 2.5{sigma} confidence) and a higher tendency to be early types (with 0.94 confidence) compared to the less isolated galaxies of subsample EIG-2. To the best of our knowledge, this is the first study that finds an effect in which an isolated sample shows a higher fraction of early types compared to a less isolated sample. Both early-type and late-type EIGs follow the same colour-to-M_*_, SFR-to-M_*_ (main sequence) and M_HI_-to-M_*_ relations. This indicates that the mechanisms and factors governing star formation, colour and the M_HI_-to-M_*_ relation are similar in early-type and late-type EIGs, and that the morphological type of EIGs is not governed by their M_HI_ content, colour or SFR.
- ID:
- ivo://CDS.VizieR/J/A+AS/106/451
- Title:
- Face-on disk galaxies photometry. I.
- Short Name:
- J/A+AS/106/451
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/MNRAS/297/885
- Title:
- Faint galaxies KIc photometry
- Short Name:
- J/MNRAS/297/885
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The excess number of blue galaxies at faint magnitudes is a subject of much controversy. Recent Hubble Space Telescope results have revealed a plethora of galaxies with peculiar morphologies tentatively identified as the evolving population. We report the results of optical spectroscopy and near-infrared photometry of a sample of faint HST galaxies from the Medium Deep Survey to ascertain the physical properties of the faint morphological populations. We find four principal results. First, the population of objects classified as 'peculiar' are intrinsically luminous in the optical (M_B_~-19). Secondly these systems tend to be strong sources of [OII] line luminosity. Thirdly the optical-infrared colours of the faint population (a) confirm the presence of a population of compact blue galaxies and (b) show the stellar populations of irregular/peculiar galaxies encompass a wide range in age. Finally a surface-brightness comparison with the local galaxy sample of Freiz et al. (1996AJ....111..174F) shows that these objects are not of anomalously low surface brightness, rather we find that all morphological classes have evolved to a higher surface brightness at higher redshifts (z>0.3).
- ID:
- ivo://CDS.VizieR/J/AJ/124/1651
- Title:
- Faint high-latitude carbon stars SDSS photometry
- Short Name:
- J/AJ/124/1651
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of 39 faint high-latitude carbon stars (FHLCs) from Sloan Digital Sky Survey (SDSS) commissioning data. The objects, each selected photometrically and verified spectroscopically, range over 16.6<r*<20.0 and show a diversity of temperatures as judged by both colors and NaD line strengths. Although a handful of these stars were previously known, these objects are, in general, too faint and too warm to be effectively identified in other modern surveys such as the Two Micron All Sky Survey, nor are their red/near-IR colors particularly distinctive. We present proper-motion measures for each object, indicating that the sample is a mixture of extremely distant (greater than 100kpc) halo giant stars, useful for constraining halo dynamics, and members of the recently recognized exotic class of very nearby dwarf carbon (dC) stars.
- ID:
- ivo://CDS.VizieR/J/AJ/127/2838
- Title:
- Faint high-latitude carbon stars SDSS photometry
- Short Name:
- J/AJ/127/2838
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A search of more than 3000deg^2^ of high-latitude sky by the Sloan Digital Sky Survey has yielded 251 faint high-latitude carbon stars (FHLCs), the large majority previously uncatalogued. We present homogeneous spectroscopy, photometry, and astrometry for the sample. The objects lie in the 15.6<r<20.8 range and exhibit a wide variety of apparent photospheric temperatures, ranging from spectral types near M to as early as F. Proper-motion measurements for 222 of the objects show that at least 50%, and quite probably more than 60%, of these objects are actually low-luminosity dwarf carbon (dC) stars, in agreement with a variety of recent, more limited investigations that show that such objects are the numerically dominant type of star with C_2_ in the spectrum. This SDSS homogeneous sample of ~110 dC stars now constitutes 90% of all known carbon dwarfs and will grow by another factor of 2-3 by the completion of the survey. As the spectra of the dC and the faint halo giant C stars are very similar (at least at spectral resolution of 10^3^), despite a difference of 10mag in luminosity, it is imperative that simple luminosity discriminants other than proper motion be developed. We use our enlarged sample of FHLCs to examine a variety of possible luminosity criteria, including many previously suggested, and find that, with certain important caveats, JHK photometry may segregate dwarfs and giants.
- ID:
- ivo://CDS.VizieR/J/AJ/152/91
- Title:
- Faint UBVRI standard stars at +50{deg} declination
- Short Name:
- J/AJ/152/91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Precise and accurate CCD-based UBVRI photometry is presented for ~2000 stars distributed around the sky in a declination zone centered approximately at +50{deg}. Their photometry has been calibrated to the standard Johnson UBV and Kron-Cousins RI systems through observations of the UBVRI standard stars presented in the various works of Landolt. The magnitude and color range for these stars are 12<~V<~22 and -0.3<~(B-V)<~1.8, respectively. Each star averages 13 measures in each UBVRI filter from data taken on 41 different photometric nights obtained over a 21 month period. Hence, there now exists a network of faint UBVRI photometric standard stars centered on the declination zones {delta}=-50{deg}, 0{deg}, and +50{deg}.
