- 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.
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- 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.
- ID:
- ivo://CDS.VizieR/J/A+AS/77/31
- Title:
- Survey at 408 MHz and 1420 MHz towards A 1314
- Short Name:
- J/A+AS/77/31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The cluster of galaxies Abell 1314 has been observed with the Penticton synthesis telescope simultaneously at 408 MHz (73.5 cm wavelength) with a sensitivity (7 rms) near 70 mJy and at 1420 MHz (21.1 cm wavelength) with a sensitivity (5 rms) near 4.3 mJy. In addition to the 3 cluster sources detected, a further 64 background radio sources have been detected at 1420 MHz (the 20P radio survey), and 169 background sources at 408 MHz (the 21P radio survey). The surveys extend to a radius of 3.7 degrees at 408 MHz, and to 1.0 degree at 1420 MHz, from the map center at RA=11h31.5m, Dec=+49d20'. The differential source count for the background radio sources, derived at 408 MHz in the flux density range 90 mJy to 3.0 Jy, shows consistency with the Cambridge 5C5 survey at 408 MHz in a direction away from clusters of galaxies. Also, the differential count derived at 1420 MHz in the flux density range 10 mJy to 330 mJy is consistent with the Westerbork LBDS survey at a nearby frequency away from clusters of galaxies. We find no candidate for very steep spectrum "relic" sources in this cluster of galaxies, nor for very flat spectrum "blue" background radio galaxies behind the cluster.
- ID:
- ivo://CDS.VizieR/J/ApJS/165/307
- Title:
- Survey for ionization in neutral gas galaxies. I.
- Short Name:
- J/ApJS/165/307
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We introduce the Survey for Ionization in Neutral Gas Galaxies (SINGG), a census of star formation in HI-selected galaxies. The survey consists of H{alpha} and R-band imaging of a sample of 468 galaxies selected from the HI Parkes All Sky Survey (HIPASS). The sample spans three decades in HI mass and is free of many of the biases that affect other star-forming galaxy samples. We present the criteria for sample selection, list the entire sample, discuss our observational techniques, and describe the data reduction and calibration methods. This paper focuses on 93 SINGG targets whose observations have been fully reduced and analyzed to date.
- ID:
- ivo://CDS.VizieR/J/ApJ/661/801
- Title:
- Survey for ionization in neutral gas galaxies. III.
- Short Name:
- J/ApJ/661/801
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the first data release from the Survey for Ionization in Neutral-Gas Galaxies (SINGG) H{alpha} survey of HI-selected galaxies to study the quantitative behavior of the diffuse, warm ionized medium (WIM) across the range of properties represented by these 109 galaxies.
- ID:
- ivo://irsa.ipac/Spitzer/Images/SAGE
- Title:
- Surveying the Agents of a Galaxy's Evolution
- Short Name:
- SAGE
- Date:
- 16 Mar 2017 01:00:00
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The Surveying the Agents of a Galaxy's Evolution (SAGE) survey covers the Large Magellanic Cloud (LMC; ~7deg×7deg) using the IRAC (3.6, 4.5, 5.8, and 8 mum) and MIPS (24, 70, and 160 mum) instruments on board the Spitzer Space Telescope. Three key science goals determined the coverage and depth of the survey. The detection of diffuse ISM with column densities >1.2×1021 H cm-2 permits detailed studies of dust processes in the ISM. SAGE's point-source sensitivity enables a complete census of newly formed stars with masses >3 Msolar that will determine the current star formation rate in the LMC. SAGE's detection of evolved stars with mass-loss rates >1×10-8 Msolar yr-1 will quantify the rate at which evolved stars inject mass into the ISM of the LMC. The observing strategy includes two epochs in 2005, separated by 3 months, that both mitigate instrumental artifacts and constrain source variability.
- ID:
- ivo://irsa.ipac/Spitzer/Images/SAGE-SMC
- Title:
- Surveying the Agents of Galaxy Evolution in the Tidally-Disrupted, Low-Metallicity Small Magellanic Cloud
- Short Name:
- SAGE-SMC
- Date:
- 27 Oct 2022 19:00:00
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The Small Magellanic Cloud (SMC) provides a unique laboratory for the study of the lifecycle of dust given its low metallicity (~1/5 solar) and relative proximity (~60 kpc). This motivated the SAGE-SMC (Surveying the Agents of Galaxy Evolution in the Tidally Stripped, Low Metallicity Small Magellanic Cloud) Spitzer Legacy program with the specific goals of studying the amount and type of dust in the present interstellar medium, the sources of dust in the winds of evolved stars, and how much dust is consumed in star formation. This program mapped the full SMC (30 deg2) including the body, wing, and tail in seven bands from 3.6 to 160 mum using IRAC and MIPS on the Spitzer Space Telescope.
- ID:
- ivo://CDS.VizieR/J/MNRAS/469/3444
- Title:
- Survey of Centaurus A's Baryonic Structures II.
- Short Name:
- J/MNRAS/469/3444
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New wide-field u'g'r'i'z' Dark Energy Camera observations centred on the nearby giant elliptical galaxy NGC 5128 covering ~21 deg^2^ are used to compile a new catalogue of ~3200 globular clusters (GCs). We report 2404 newly identified candidates, including the vast majority within ~140kpc of NGC 5128. We find evidence for a transition at a galactocentric radius of R_gc_~=55kpc from GCs 'intrinsic' to NGC 5128 to those likely to have been accreted from dwarf galaxies or that may transition to the intragroup medium of the Centaurus A galaxy group. We fit power-law surface number density profiles of the form {Sigma}_N,R_gc_{prop.to}R_gc_^{Gamma}^ and find that inside the transition radius, the red GCs are more centrally concentrated than the blue, with {Gamma}_inner,red_~=-1.78 and {Gamma}_inner,blue_~=-1.40, respectively. Outside this region both profiles flatten, more dramatically for the red GCs ({Gamma}_outer,red_~=-0.33) compared to the blue ({Gamma}_outer,blue_~= -0.61), although the former is more likely to suffer contamination by background sources. The median (g'-z')_0_=1.27mag colour of the inner red population is consistent with arising from the amalgamation of two giant galaxies each less luminous than present-day NGC 5128. Both inwards and outwards of the transition radius, we find the fraction of blue GCs to dominate over the red GCs, indicating a lively history of minor mergers. Assuming the blue GCs to originate primarily in dwarf galaxies, we model the population required to explain them, while remaining consistent with NGC 5128's present-day spheroid luminosity. We find that several dozen dwarfs of luminosities L_dw,V_~= 10^6-9.3^L_V,{sun}_, following a Schechter luminosity function with a faint-end slope of -1.50<={alpha}<=-1.25 is favoured, many of which may have already been disrupted in NGC 5128's tidal field.
