- ID:
- ivo://CDS.VizieR/J/MNRAS/435/2835
- Title:
- Morphological types from Galaxy Zoo 2
- Short Name:
- J/MNRAS/435/2835
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the data release for Galaxy Zoo 2 (GZ2), a citizen science project with more than 16 million morphological classifications of 304122 galaxies drawn from the Sloan Digital Sky Survey (SDSS). Morphology is a powerful probe for quantifying a galaxy's dynamical history; however, automatic classifications of morphology (either by computer analysis of images or by using other physical parameters as proxies) still have drawbacks when compared to visual inspection. The large number of images available in current surveys makes visual inspection of each galaxy impractical for individual astronomers. GZ2 uses classifications from volunteer citizen scientists to measure morphologies for all galaxies in the DR7 Legacy survey with m_r_>17, in addition to deeper images from SDSS Stripe 82. While the original GZ2 project identified galaxies as early-types, late-types or mergers, GZ2 measures finer morphological features. These include bars, bulges and the shapes of edge-on discs, as well as quantifying the relative strengths of galactic bulges and spiral arms. This paper presents the full public data release for the project, including measures of accuracy and bias. The majority (>90 per cent) of GZ2 classifications agree with those made by professional astronomers, especially for morphological T-types, strong bars and arm curvature. Both the raw and reduced data products can be obtained in electronic format at http://data.galaxyzoo.org .
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/217/27
- Title:
- Morphologies of z<0.01 SDSS-DR7 galaxies
- Short Name:
- J/ApJS/217/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The morphological types of 5836 galaxies were classified by a visual inspection of color images using the Sloan Digital Sky Survey Data Release 7 to produce a morphology catalog of a representative sample of local galaxies with z<0.01. The sample galaxies are almost complete for galaxies brighter than r_pet_=17.77. Our classification system is basically the same as that of the Third Reference Catalog of Bright Galaxies with some simplifications for giant galaxies. On the other hand, we distinguish the fine features of dwarf elliptical (dE)-like galaxies to classify five subtypes: dE, blue-cored dwarf ellipticals, dwarf spheroidals (dSph), blue dwarf ellipticals (dE_blue_), and dwarf lenticulars (dS0). In addition, we note the presence of nucleation in dE, dSph, and dS0. Elliptical galaxies and lenticular galaxies contribute only ~1.5 and 4.9% of local galaxies, respectively, whereas spirals and irregulars contribute ~32.1 and ~42.8%, respectively. The dE_blue_ galaxies, which are a recently discovered population of galaxies, contribute a significant fraction of dwarf galaxies. There seem to be structural differences between dSph and dE galaxies. The dSph galaxies are fainter and bluer with a shallower surface brightness gradient than dE galaxies. They also have a lower fraction of galaxies with small axis ratios (b/a<~0.4) than dE galaxies. The mean projected distance to the nearest neighbor galaxy is ~260 kpc. About 1% of local galaxies have no neighbors with comparable luminosity within a projected distance of 2Mpc.
- ID:
- ivo://CDS.VizieR/J/AJ/146/151
- Title:
- Morphology catalog of nearby galaxies from SDSS DR7
- Short Name:
- J/AJ/146/151
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the statistical properties of a volume-limited sample of 7429 nearby (z=0.033-0.044) galaxies from the Sloan Digital Sky Survey Data Release 7. Our database includes morphology distribution as well as the structural and spectroscopic properties of each morphology type based on the recent remeasurements of spectral line strengths by Oh and collaborators. Our database does not include galaxies that are apparently smaller and flatter because morphology classification of them turned out to be difficult. Our statistics confirmed the up-to-date knowledge of galaxy populations, e.g., correlations between morphology and line strengths as well as the derived ages. We hope that this database will be useful as a reference.
- ID:
- ivo://CDS.VizieR/J/ApJS/141/61
- Title:
- Morphology of satellite galaxies
- Short Name:
- J/ApJS/141/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results of an ongoing project to study the morphological, kinematical, dynamical, and chemical properties of satellite galaxies of external giant spiral galaxies. The sample of objects has been selected from the catalog by Zaritsky et al. (1993ApJ...405..464Z). The paper analyzes the morphology and structural parameters of a subsample of 60 such objects. The satellites span a great variety of morphologies and surface brightness profiles. About two-thirds of the sample are spirals and irregulars, the remaining third being early-types. Some cases showing interaction between pairs of satellites are presented and briefly discussed.
- ID:
- ivo://CDS.VizieR/J/ApJ/886/40
- Title:
- Most luminous SPIRITS IR transients follow-up obs.
- Short Name:
- J/ApJ/886/40
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a systematic study of the most luminous (MIR [Vega magnitudes] brighter than -14) infrared (IR) transients discovered by the SPitzer InfraRed Intensive Transients Survey (SPIRITS) between 2014 and 2018 in nearby galaxies (D<35Mpc). The sample consists of nine events that span peak IR luminosities of M_[4.5],peak_ between -14 and -18.2, show IR colors between 0.2<([3.6]-[4.5])<3.0, and fade on timescales between 55d<t_fade_<480d. The two reddest events (A_V_>12) show multiple, luminous IR outbursts over several years and have directly detected, massive progenitors in archival imaging. With analyses of extensive, multiwavelength follow-up, we suggest the following possible classifications: five obscured core-collapse supernovae (CCSNe), two erupting massive stars, one luminous red nova, and one intermediate-luminosity red transient. We define a control sample of all optically discovered transients recovered in SPIRITS galaxies and satisfying the same selection criteria. The control sample consists of eight CCSNe and one Type Iax SN. We find that 7 of the 13 CCSNe in the SPIRITS sample have lower bounds on their extinction of 2<A_V_<8. We estimate a nominal fraction of CCSNe in nearby galaxies that are missed by optical surveys as high as 38.5_-21.9_^+26.0^% (90% confidence). This study suggests that a significant fraction of CCSNe may be heavily obscured by dust and therefore undercounted in the census of nearby CCSNe from optical searches.
- ID:
- ivo://CDS.VizieR/J/A+A/415/863
- Title:
- Mount Stromlo Abell Cluster Supernova Search
- Short Name:
- J/A+A/415/863
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table 1 lists SNe discovered by the Mount Stromlo Abell Cluster Supernova Search. The SNIa? were classified through the goodness of fit of the template light curves and hence could be SNe of another type that have been misclassified. Those SNe designated nIa were deemed not to be SNIa through the template fits and were not investigated further. Table 3 contains Maximum light magnitudes, {Delta}m15 values and distances derived from the template light curve fitting technique for those SNe from the Mount Stromlo Abell Cluster Supernova Search deemed to be SNIa, as well as those from Phillips (1999AJ....118.1766P) The subdirectory "comp" contains the files with calibrated magnitudes for the local standard stars found in the field of each of the supernovae from the Mount Stromlo Abell Cluster Supernova Search. The numbering of these stars corresponds to that found in the finding charts of each of these fields. These are found online at EDP Sciences. For each local standard, their Cousins B, V, R and I magnitudes are given, as is the error in the magnitude estimate. The subdirectory "flux" contains the files with calibrated fluxes for the supernovae discovered in the Mount Stromlo Abell Cluster Supernova Search. For each supernova, the MACHO VM, RM magnitudes and Cousins B, V, R and I fluxes are given (when available), as are the errors in the derived fluxes. One unit flux is equivalent to 25th magnitude. The subdirectory "mag" contains the files with calibrated magnitudes for the supernovae discovered in the Mount Stromlo Abell Cluster Supernova Search. For each supernova, the MACHO VM, RM magnitudes and Cousins B, V, R and I magnitudes are given (when available), as is the upper and lower errors in the derived magnitudes.
- ID:
- ivo://CDS.VizieR/J/PASP/113/267
- Title:
- Mount Wilson catalogue photometric properties
- Short Name:
- J/PASP/113/267
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper is partly a review of the history of the making of the Mount Wilson Catalogue of Photographic Magnitudes in Selected Areas 1-139 (hereafter the MWC), begun in 1909 and completed in 1930, and it is partly the presentation of new photometric results concerning it. Photoelectric photometry of 435 stars in the 11 Selected Areas of SA 28, 29, 45, 55, 57, 71, 82, 94, 106, 107, and 118 of the MWC is given. The data are used to derive magnitude corrections to the MWC for these areas. Ten of the areas are in the Galactic meridional plane (Galactic longitudes of 0{deg} and 180{deg}). These are the same areas used by Becker in his Basel program of star counts for the study of Galactic structure.
- ID:
- ivo://CDS.VizieR/J/AJ/124/234
- Title:
- M31 outer halo UBVRI photometry and metallicity
- Short Name:
- J/AJ/124/234
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present first results from a spectroscopic survey designed to examine the metallicity and kinematics of individual red giant branch stars in the outer halo of the Andromeda spiral galaxy (M31). This study is based on multislit spectroscopy with the Keck II 10m telescope and Low Resolution Imaging Spectrograph of the Ca II near-infrared triplet in 99 M31 halo candidates in a field at R=19kpc on the southeast minor axis with brightnesses from 20<I<22.
- ID:
- ivo://CDS.VizieR/J/ApJ/864/59
- Title:
- M31 PAndromeda Cepheid sample in four HST bands
- Short Name:
- J/ApJ/864/59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the M31 PAndromeda Cepheid sample and the HST PHAT data we obtain the largest Cepheid sample in M31 with HST data in four bands. For our analysis we consider three samples: A very homogeneous sample of Cepheids based on the PAndromeda data, the mean magnitude corrected PAndromeda sample and a sample complementing the PAndromeda sample with Cepheids from literature. The latter results in the largest catalog with 522 fundamental mode (FM) Cepheids and 102 first overtone (FO) Cepheids with F160W and F110W data and 559 FM Cepheids and 111 FO Cepheids with F814W and F475W data. The obtained dispersion of the Period-Luminosity relations (PLRs) is very small (e.g. 0.138mag in the F160W sample I PLR). We find no broken slope in the PLRs when analyzing our entire sample, but we do identify a subsample of Cepheids that causes the broken slope. However, this effect only shows when the number of this Cepheid type makes up a significant fraction of the total sample. We also analyze the sample selection effect on the Hubble constant.
- ID:
- ivo://CDS.VizieR/J/A+A/290/69
- Title:
- M3 photographic photometry
- Short Name:
- J/A+A/290/69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new photographic colour-magnitude diagram for the Galactic globular cluster M 3 is presented.
