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- ID:
- ivo://CDS.VizieR/J/ApJS/85/249
- Title:
- Surface Photometry of Hydra I Galaxies. I.
- Short Name:
- J/ApJS/85/249
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Surface photometry was made for 137 galaxies on a UK Schmidt plate whose center is located at the center of the Hydra I (A1060) cluster of galaxies. For 133 of 137 galaxies the photometric parameters such as total magnitude, equivalent radius, concentration indices, and mean surface brightness were obtained. The total magnitudes were compared with those in the literature to check the accuracy of the present data. The estimated accuracy in the total magnitudes is about 0.1 mag at most for majority of the galaxies. This catalog is an updated version from the published paper.
- ID:
- ivo://CDS.VizieR/J/MNRAS/384/1544
- Title:
- Surface photometry of local dwarf galaxies
- Short Name:
- J/MNRAS/384/1544
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present surface photometry and metallicity measurements for 104 nearby dwarf galaxies imaged with the Advanced Camera for Surveys and Wide Field and Planetary Camera 2 aboard the Hubble Space Telescope. In addition, we carried out photometry for 26 galaxies of the sample and for Sextans B on images of the Sloan Digital Sky Survey. Our sample comprises dwarf spheroidal, irregular and transition type galaxies located within ~10Mpc in the field and in nearby groups: M81, Centaurus A, Sculptor and Canes Venatici I cloud. It is found that the early-type galaxies have on average higher metallicity at a given luminosity in comparison to the late-type objects. Dwarf galaxies with MB>=-12 to -13mag deviate towards larger scalelengths from the scalelength-luminosity relation common for spiral galaxies, h{prop.to}L^0.5^_B_.
- ID:
- ivo://CDS.VizieR/J/ApJS/126/271
- Title:
- Surface photometry of nearby field galaxies
- Short Name:
- J/ApJS/126/271
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained integrated spectra and multifilter photometry for a representative sample of ~200 nearby galaxies. These galaxies span the entire Hubble sequence in morphological type, as well as a wide range of luminosities (M_B_=-14 to -22) and colors (B-R=0.4-1.8). Here we describe the sample selection criteria and the U, B, R surface photometry for these galaxies. The spectrophotometric results will be presented in a companion paper (Cat. <J/ApJS/126/331>).
- ID:
- ivo://CDS.VizieR/J/AJ/117/2757
- Title:
- Surface photometry of NGC 5907
- Short Name:
- J/AJ/117/2757
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Intrigued by the initial report of an extended luminosity distribution perpendicular to the disk of the edge-on Sc galaxy NGC 5907, we have obtained very deep exposures of this galaxy with a Schmidt telescope, large-format CCD, and intermediate-band filters centered at 6660 {AA} and 8020 {AA}. These two filters, part of a 15-filter set, are custom designed to avoid the brightest (and most variable) night skylines. As a result, our images are able to go deeper with lower sky noise than those taken with broadband filters at similar effective wavelengths: e.g., 0.6 e^-^ arcsec^-2^ s^-1^ for our observations versus 7.4 e^-^ arcsec^-2^ s-1 for the R-band measures of Morrison et al. (1994AJ....108.1191M). In our assessment of both random and systematic errors, we show that the flux level where the errors of observation reach 1 mag arcsec^-2^ are 29.00 mag arcsec^-2^ in the 6660 {AA} image (corresponding to 28.7 in the R band) and 27.4 mag arcsec^-2^ in the 8020 {AA} image (essentially on the I-band system)
- ID:
- ivo://CDS.VizieR/J/ApJS/182/216
- Title:
- Surface photometry of Virgo ellipticals
- Short Name:
- J/ApJS/182/216
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New surface photometry of all known elliptical galaxies in the Virgo cluster is combined with published data to derive composite profiles of brightness, ellipticity, position angle, isophote shape, and color over large radius ranges. These provide enough leverage to show that Sersic logI{prop.to}r^1/n^ functions fit the brightness profiles I(r) of nearly all ellipticals remarkably well over large dynamic ranges. Therefore, we can confidently identify departures from these profiles that are diagnostic of galaxy formation. Finally, we verify that there is a strong dichotomy between elliptical and spheroidal galaxies. Their properties are consistent with our understanding of their different formation processes: mergers for ellipticals and conversion of late-type galaxies into spheroidals by environmental effects and by energy feedback from supernovae.
- ID:
- ivo://CDS.VizieR/J/ApJS/255/17
- Title:
- Surface rotation & activity for Kepler stars. II.
- Short Name:
- J/ApJS/255/17
- Date:
- 25 Nov 2021 08:29:49
- Publisher:
- CDS
- Description:
- Dark magnetic spots crossing the stellar disk lead to quasiperiodic brightness variations, which allow us to constrain stellar surface rotation and photometric activity. The current work is the second of this series, where we analyze the Kepler long-cadence data of 132,921 main-sequence F and G stars and late subgiant stars. Rotation-period candidates are obtained by combining wavelet analysis with autocorrelation function. Reliable rotation periods are then selected via a machine-learning (ML) algorithm, automatic selection, and complementary visual inspection. The ML training data set comprises 26,521 main-sequence K and M stars from Paper I (Santos+ 2019, J/ApJS/244/21). To supplement the training, we analyze in the same way as Paper I, i.e., automatic selection and visual inspection, 34,100 additional stars. We finally provide rotation periods P_rot_ and associated photometric activity proxy S_ph_ for 39,592 targets. Hotter stars are generally faster rotators than cooler stars. For main-sequence G stars, S_ph_ spans a wider range of values with increasing effective temperature, while F stars tend to have smaller S_ph_ values in comparison with cooler stars. Overall for G stars, fast rotators are photometrically more active than slow rotators, with S_ph_ saturating at short periods. The combined outcome of the two papers accounts for average P_rot_ and S_ph_ values for 55,232 main-sequence and subgiant FGKM stars (out of 159,442 targets), with 24,182 new P_rot_ detections in comparison with McQuillan+ (2014, J/ApJS/211/24). The upper edge of the P_rot_ distribution is located at longer P_rot_ than found previously.
- ID:
- ivo://CDS.VizieR/J/ApJS/244/21
- Title:
- Surface rotation & activity of Kepler stars. I.
- Short Name:
- J/ApJS/244/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Brightness variations due to dark spots on the stellar surface encode information about stellar surface rotation and magnetic activity. In this work, we analyze the Kepler long-cadence data of 26521 main-sequence stars of spectral types M and K in order to measure their surface rotation and photometric activity level. Rotation-period estimates are obtained by the combination of a wavelet analysis and autocorrelation function of the light curves. Reliable rotation estimates are determined by comparing the results from the different rotation diagnostics and four data sets. We also measure the photometric activity proxy S_ph_ using the amplitude of the flux variations on an appropriate timescale. We report rotation periods and photometric activity proxies for about 60% of the sample, including 4431 targets for which McQuillan+ (2014, J/ApJS/211/24) did not report a rotation period. For the common targets with rotation estimates in this study and in McQuillan+, our rotation periods agree within 99%. In this work, we also identify potential polluters, such as misclassified red giants and classical pulsator candidates. Within the parameter range we study, there is a mild tendency for hotter stars to have shorter rotation periods. The photometric activity proxy spans a wider range of values with increasing effective temperature. The rotation period and photometric activity proxy are also related, with S_ph_ being larger for fast rotators. Similar to McQuillan+, we find a bimodal distribution of rotation periods.
- ID:
- ivo://CDS.VizieR/J/A+A/605/A111
- Title:
- Surface rotation of Kepler red giant stars
- Short Name:
- J/A+A/605/A111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Kepler allows the measurement of starspot variability in a large sample of field red giants for the first time. With a new method that combines autocorrelation and wavelet decomposition, we measure 361 rotation periods from the full set of 17,377 oscillating red giants in our sample. This represents 2.08% of the stars, consistent with the fraction of spectroscopically detected rapidly rotating giants in the field. The remaining stars do not show enough variability to allow us to measure a reliable surface rotation period. Because the stars with detected rotation periods have measured oscillations, we can infer their global properties, e.g. mass and radius, and quantitatively evaluate the predictions of standard stellar evolution models as a function of mass. Consistent with results for cluster giants, when we consider only the 4881 intermediate-mass stars, M>2.0M_{sun}_from our full red giant sample, we do not find the enhanced rates of rapid rotation one would expect from angular momentum conservation. We therefore suggest that either enhanced angular momentum loss or radial differential rotation must be occurring in these stars. Finally, when we examine the 575 low-mass (M<1.1M_{sun}_) red clump stars in our sample, which we would have expected to exhibit slow (non-detectable) rotation, 15% of them actually have detectable rotation. This suggests a high rate of interactions and stellar mergers on the red giant branch.
- ID:
- ivo://CDS.VizieR/J/A+AS/75/67
- Title:
- Survey around the North Ecliptic Pole at 11 cm
- Short Name:
- J/A+AS/75/67
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains a survey of a rectangular area of 10x6 degrees in galactic coordinates (95.5{deg} < l < 101.5{deg} ; 28{deg} < b < 38{deg}) in the radio continuum in the direction of the north ecliptic pole (RA=18h, Dec=66.5{deg}) at 11.1 cm wavelength. The survey was conducted with the 100m radio telescope of the Max Planck Institut fur Radioastronomie. 469 sources were detected with an integrated flux density greater than 11 mJy, and with an angular resolution of 4.35'. The survey is believed to be complete to at least the 35 mJy level and can be used for comparison with deep surveys in other wavelengths of this area.