- ID:
- ivo://CDS.VizieR/J/ApJ/708/841
- Title:
- Star formation in E/S0 galaxies
- Short Name:
- J/ApJ/708/841
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent work has identified a population of low-redshift E/S0 galaxies that lie on the blue sequence in color versus stellar mass parameter space, where spiral galaxies typically reside. While high-mass blue-sequence E/S0s often resemble young merger or interaction remnants likely to fade to the red sequence, we focus on blue-sequence E/S0s with lower stellar masses (M_*_<a fewx10^10^M_{sun}_), which are characterized by fairly regular morphologies and low-density field environments where fresh gas infall is possible. This population may provide an evolutionary link between early-type galaxies and spirals through disk regrowth. Focusing on atomic gas reservoirs, we present new GBT HI data for 27 E/S0s on both sequences as well as a complete tabulation of archival HI data for other galaxies in the Nearby Field Galaxy Survey. Normalized to stellar mass, the atomic gas masses for 12 of the 14 blue-sequence E/S0s range from 0.1 to >1.0, demonstrating that morphological transformation is possible if the detected gas can be converted into stars. These gas-to-stellar mass ratios are comparable to those of spiral and irregular galaxies and have a similar dependence on stellar mass.
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- ID:
- ivo://CDS.VizieR/J/ApJ/613/914
- Title:
- Star formation in HI-selected galaxies
- Short Name:
- J/ApJ/613/914
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A sample of 69 galaxies with radial velocities of less than 2500km/s was selected from the HI Parkes All-Sky Survey (HIPASS, Cat. <VIII/73>) and imaged in broadband B and R and narrowband H{alpha}, to deduce details about star formation in nearby disk galaxies while avoiding surface brightness selection effects.
- ID:
- ivo://CDS.VizieR/J/other/AstBu/68.243
- Title:
- Star formation in isolated galaxies
- Short Name:
- J/other/AstBu/68
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the FUV fluxes measured with the GALEX to study the star formation properties of galaxies collected in the Local Orphan Galaxies catalog (LOG, 2011AstBu..66....1K). Among 517 LOG galaxies having radial velocities V_LG_<3500km/s and Galactic latitudes |b|>15{deg}, 428 objects have been detected in FUV. We briefly discuss some scaling relations between the specific star formation rate (SSFR) and stellar mass, HI-mass, morphology, and surface brightness of galaxies situated in extremely low density regions of the Local Supercluster. Our sample is populated with predominantly late-type, gas-rich objects with the median morphological type of Sdm. Only 5% of LOG galaxies are classified as early types: E, S0, S0/a, however, they systematically differ from normal E and S0 galaxies by lower luminosity and presence of gas and dust. We find that almost all galaxies in our sample have their SSFR below 0.4Gyr^-1^. This limit is also true even for a sample of 260 active star-burst Markarian galaxies situated in the same volume. The existence of such a quasi-Eddington limit for galaxies seems to be a key factor which characterizes the transformation of gas into stars at the current epoch.
- ID:
- ivo://CDS.VizieR/J/A+A/588/A29
- Title:
- Star formation in massive clumps in Milky Way
- Short Name:
- J/A+A/588/A29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Newborn stars form within the localized, high density regions of molecular clouds. The sequence and rate at which stars form in dense clumps and the dependence on local and global environments are key factors in developing descriptions of stellar production in galaxies. We seek to observationally constrain the rate and latency of star formation in dense massive clumps that are distributed throughout the Galaxy and to compare these results to proposed prescriptions for stellar production. A sample of 24 micron based Class I protostars are linked to dust clumps that are embedded within molecular clouds selected from the APEX Telescope Large Area Survey of the Galaxy. We determine the fraction of star-forming clumps that imposes a constraint on the latency of star formation in units of a clump's lifetime. Protostellar masses are estimated from models of circumstellar environments of young stellar objects from which star formation rates are derived. Physical properties of the clumps are calculated from 870 micron dust continuum emission and NH_3_ line emission. Linear correlations are identified between the star formation rate surface density, Sigma_SFR and the quantities Sigma_H2/tau_ff and Sigma_H2/tau_cross, suggesting that star formation is regulated at the local scales of molecular clouds. The measured fraction of star forming clumps is 23%. Accounting for star formation within clumps that are excluded from our sample due to 24 micron saturation, this fraction can be as high as 31%, which is similar to previous results. Dense, massive clumps form primarily low mass (<1-2M_{sun}_) stars with emergent 24 micron fluxes below our sensitivity limit or are incapable of forming any stars for the initial 70% of their lifetimes. The low fraction of star forming clumps in the Galactic center relative to those located in the disk of the Milky Way is verified.
- ID:
- ivo://nasa.heasarc/sfincspcm
- Title:
- Star Formation in Nearby Clouds (SFiNCs) Probable Cluster Members Catalog
- Short Name:
- SFINCSPCM
- Date:
- 09 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Star Formation in Nearby Clouds (SFiNCs) project is aimed at providing a detailed study of the young stellar populations and of star cluster formation in the nearby 22 star-forming regions (SFRs) for comparison with the authors' earlier MYStIX survey of richer, more distant clusters. As a foundation for the SFiNCs science studies, in the reference paper homogeneous data analyses of the Chandra X-ray and Spitzer mid-infrared (MIR) archival SFiNCs data are described, and the resulting catalogs of over 15,300 X-ray and over 1,630,000 mid-infrared point sources are presented. On the basis of their X-ray/infrared properties and spatial distributions, nearly 8500 point sources have been identified as probable young stellar members of the SFiNCs regions. Compared to the existing X-ray/mid-infrared publications, the SFiNCs member list increases the census of YSO members by 6%-200% for individual SFRs and by 40% for the merged sample of all 22 SFiNCs SFRs. Sixty-five X-ray observations of the 22 SFiNCs SFRs made with the imaging array on the Advanced CCD Imaging Spectrometer (ACIS) were extracted from the Chandra archive (spanning from 2000 January to 2015 April). See Tables 1 and 2 of the reference paper for the list of SFRs and the log of Chandra ACIS observations, respectively. The final Chandra-ACIS catalog for the 22 SFiNCs SFRs comprises 15,364 X-ray sources (presented in Tables 3 and 4 and section 3.2 of the reference paper, and available as the HEASARC table, SFINCSXRAY). To obtain MIR photometry for X-ray objects and to identify and measure MIR photometry for additional non-Chandra disky stars that were missed in previous studies of the SFiNCs regions (typically faint YSOs), the authors have reduced the archived Spitzer-IRAC data by homogeneously applying the MYStIX-based Spitzer-IRAC data reduction methods of Kuhn et al. (2013, ApJS, 209, 29) to the 423 Astronomical Object Request (AORs) data sets for the 22 SFiNCs SFRs (listed in Table 5 of the reference paper). As in MYStIX, the SFiNCs IRAC source catalog retains all point sources with the photometric signal-to-noise ratio > 5 in both [3.6] and [4.5] um channels. This catalog covers the 22 SFiNCs SFRs and their vicinities on the sky and comprises 1,638,654 IRAC sources with available photometric measurements for 100%, 100%, 29%, and 23% of these sources in the 3.6, 4.5, 5.8, and 8.0um bands, respectively (see table 6 and section 3.4 of the reference paper). Source position cross-correlations between the SFiNCs Chandra X-ray source catalog and an IR catalog, either the "cut-out" IRAC or 2MASS, were made using the steps described in section 3.5 of the reference paper. Using the ensemble of X-ray and infrared data that they have obtained, the authors selected probable YSOs in the 22 SFRs using selection criteria described in section 4.1 of the reference paper. Tables 7 and 8 of the reference paper provide the list of 8,492 SFiNCs probable cluster members (SPCMs: but see below for a caveat on this number) and their main IR and X-ray properties (see section 4 of the reference paper). This present HEASARC table comprises the contents of these two tables. A fuller list of the X-ray properties of the X-ray-detected SPCMs is available in the HEASARC's SFINCSXRAY table (q.v.). This table was created by the HEASARC in September 2017 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/229/28">CDS Catalog J/ApJS/229/28</a> files table7.dat (the IR photometry of the SFiNCs probable cluster members) and table8.dat (the main X-ray and other properties of the SFiNCs probable cluster members). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/sfincsxray
- Title:
- Star Formation in Nearby Clouds (SFiNCs) X-Ray Source Catalog
- Short Name:
- SFINCSXRAY
- Date:
- 09 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Star Formation in Nearby Clouds (SFiNCs) project is aimed at providing a detailed study of the young stellar populations and of star cluster formation in the nearby 22 star-forming regions (SFRs) for comparison with our earlier MYStIX survey of richer, more distant clusters. As a foundation for the SFiNCs science studies, in the reference paper homogeneous data analyses of the Chandra X-ray and Spitzer mid-infrared archival SFiNCs data are described, and the resulting catalogs of over 15,300 X-ray and over 1,630,000 mid-infrared point sources are presented. On the basis of their X-ray/infrared properties and spatial distributions, nearly 8500 point sources have been identified as probable young stellar members of the SFiNCs regions. Compared to the existing X-ray/mid-infrared publications, the SFiNCs member list increases the census of YSO members by 6%-200% for individual SFRs and by 40% for the merged sample of all 22 SFiNCs SFRs. Sixty-five X-ray observations of the 22 SFiNCs SFRs made with the imaging array on the Advanced CCD Imaging Spectrometer (ACIS) were extracted from the Chandra archive (spanning from 2000 January to 2015 April). See Tables 1 and 2 of the reference paper for the list of SFRs and the log of Chandra ACIS observations, respectively. The final Chandra-ACIS catalog for the 22 SFiNCs SFRs comprises 15,364 X-ray sources (presented in Tables 3 and 4 and section 3.2 of the reference paper, and the contents of this HEASARC table, SFINCSXRAY). To obtain MIR photometry for X-ray objects and to identify and measure MIR photometry for additional non-Chandra disky stars that were missed in previous studies of the SFiNCs regions (typically faint YSOs), the authors have reduced the archived Spitzer-IRAC data by homogeneously applying the MYStIX-based Spitzer-IRAC data reduction methods of Kuhn et al. (2013, ApJS, 209, 29) to the 423 Astronomical Object Request (AORs) data sets for the 22 SFiNCs SFRs (Table 5 of the reference paper). As in MYStIX, the SFiNCs IRAC source catalog retains all point sources with the photometric signal-to-noise ratio > 5 in both [3.6] and [4.5] um channels. This catalog covers the 22 SFiNCs SFRs and their vicinities on the sky and comprises 1,638,654 IRAC sources with available photometric measurements for 100%, 100%, 29%, and 23% of these sources in the 3.6, 4.5, 5.8, and 8.0um bands, respectively (see table 6 and section 3.4 of the reference paper). Source position cross-correlations between the SFiNCs Chandra X-ray source catalog and an IR catalog, either the "cut-out" IRAC or 2MASS, were made using the steps described in section 3.5 of the reference paper. Tables 7 and 8 of the reference paper provide the list of 8,492 SFiNCs probable cluster members (SPCMs) and their main IR and X-ray properties (see section 4 of the reference paper): this list as available at the HEASARC as the SFINCSPCM table (q.v.). This table was created by the HEASARC in September 2017 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/229/28">CDS Catalog J/ApJS/229/28</a> files table3.dat (the list of SFiNCs X-ray sources and their basic properties) and table4.dat (the list of SFiNCs X-ray source fluxes). This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/ApJS/174/337
- Title:
- Star formation in nuclear rings
- Short Name:
- J/ApJS/174/337
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a photometric H{alpha} survey of 22 nuclear rings, aiming to provide insight into their star formation properties, including age distribution, dynamical timescales, star formation rates, and galactic bar influence. We find a clear relationship between the position angles and ellipticities of the rings and those of their host galaxies, which indicates the rings are in the same plane as the disk and circular. We use population synthesis models to estimate ages of each H{alpha}-emitting (HII) region, which range from 1 to 10Myr throughout the rings. We find that approximately half of the rings contain azimuthal age gradients that encompass at least 25% of the ring, although there is no apparent relationship between the presence or absence of age gradients and the morphology of the rings or their host galaxies. NGC 1343, NGC 1530, and NGC 4321 show clear bipolar age gradients, where the youngest HII regions are located near the two contact points of the bar and ring. We speculate in these cases that the gradients are related to an increased mass inflow rate and/or an overall higher gas density in the ring, which would allow for massive star formation to occur on short timescales, after which the galactic rotation would transport the HII regions around the ring as they age. Two-thirds of the barred galaxies show correlation between the locations of the youngest HII region(s) in the ring and the location of the contact points, which is consistent with predictions from numerical modeling.
- ID:
- ivo://CDS.VizieR/J/ApJ/683/822
- Title:
- Star formation in Ophiuchus and Perseus II.
- Short Name:
- J/ApJ/683/822
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a census of the population of deeply embedded young stellar objects (YSOs) in the Ophiuchus molecular cloud complex based on a combination of Spitzer Space Telescope mid-infrared data from the "Cores to Disks" (c2d) legacy team and JCMT/SCUBA submillimeter maps from the COMPLETE team. We have applied a method developed for identifying embedded protostars in Perseus to these data sets and in this way construct a relatively unbiased sample of 27 candidate embedded protostars with envelopes more massive than our sensitivity limit (about 0.1M_{sun}_).
- ID:
- ivo://CDS.VizieR/J/A+A/468/1009
- Title:
- Star formation in Perseus. II.
- Short Name:
- J/A+A/468/1009
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Hatchell et al. (2005, Cat. <J/A+A/440/151>, Paper I) published a submillimetre continuum map of the Perseus molecular cloud, detecting the starless and protostellar cores within it. The aim is to determine the evolutionary stage of each submm core in Perseus, and investigate the lifetimes of these phases.
- ID:
- ivo://CDS.VizieR/J/ApJ/761/97
- Title:
- Star Formation in Radio Survey (SFRS): 33GHz obs.
- Short Name:
- J/ApJ/761/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 33GHz photometry of 103 galaxy nuclei and extranuclear star-forming complexes taken with the Green Bank Telescope (GBT) as part of the Star Formation in Radio Survey (SFRS). Among the sources without evidence for an active galactic nucleus, and also having lower frequency radio data, we find a median thermal fraction at 33GHz of {approx}76% with a dispersion of {approx}24%. For all sources resolved on scales <~0.5kpc, the thermal fraction is even larger, being >~90%. This suggests that the rest-frame 33GHz emission provides a sensitive measure of the ionizing photon rate from young star-forming regions, thus making it a robust star formation rate (SFR) indicator. Taking the 33 GHz SFRs as a reference, we investigate other empirical calibrations relying on different combinations of warm 24{mu}m dust, total infrared (IR; 8-1000{mu}m), H{alpha} line, and far-UV continuum emission. The recipes derived here generally agree with others found in the literature, albeit with a large dispersion that most likely stems from a combination of effects. Comparing the 33GHz to total IR flux ratios as a function of the radio spectral index, measured between 1.7 and 33GHz, we find that the ratio increases as the radio spectral index flattens which does not appear to be a distance effect. Consequently, the ratio of non-thermal to total IR emission appears relatively constant, suggesting only moderate variations in the cosmic-ray electron injection spectrum and ratio of synchrotron to total cooling processes among star-forming complexes. Assuming that this trend solely arises from an increase in the thermal fraction sets a maximum on the scatter of the non-thermal spectral indices among the star-forming regions of {sigma}_{alpha}_NT<~0.13.
![To the extent possible under law, the publisher has waived all copyright and related or neighboring rights to the catalogue of astrometric microlensing events. For details, see the `Creative Commons CC0 1.0 Public Domain dedication <http://creativecommons.org/publicdomain/zero/1.0/>`_. Of course, you should still give proper credit when using this data as required by good scientific practice. .. image:: /static/img/cc0.png :alt: [CC0]](/registry-search/?f%5BcapabilityType_facet%5D%5B%5D=Simple+Cone+Search&f%5Brights_facet%5D%5B%5D=To+the+extent+possible+under+law%2C+the+publisher+has+waived+all+copyright+and+related+or+neighboring+rights+to+the+catalogue+of+astrometric+++microlensing+events.++For+details%2C+see+the+%60Creative+Commons+CC0+1.0+Public+Domain+dedication+%3Chttp%3A%2F%2Fcreativecommons.org%2Fpublicdomain%2Fzero%2F1.0%2F%3E%60_.++Of+course%2C+you+should+still+give+proper+credit+when+using+this+data+as+required+by+good+scientific+practice.%0A%0A..+image%3A%3A+%2Fstatic%2Fimg%2Fcc0.png%0A+++%3Aalt%3A+%5BCC0%5D%0A%0A){kind=link}