- ID:
- ivo://CDS.VizieR/J/MNRAS/344/181
- Title:
- PDS versus Markarian starburst galaxies
- Short Name:
- J/MNRAS/344/181
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The characteristics of the starburst galaxies from the Pico dos Dias Survey (PDS, Coziol et al., 1998ApJS..119..239C) are compared with those of the nearby ultraviolet (UV) bright Markarian starburst galaxies, having the same limit in redshift (v_h_<7500km/s) and absolute B magnitude (M_B_<18). An important difference is found: the Markarian galaxies are generally undetected at 12 and 25um in IRAS. This is consistent with the UV excess shown by these galaxies and suggests that the youngest star-forming regions dominating these galaxies are relatively free of dust.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/135/1624
- Title:
- PEARS emission-line galaxies
- Short Name:
- J/AJ/135/1624
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Hubble Space Telescope Advanced Camera for Surveys grism Probing Evolution And Reionization Spectroscopically (PEARS) survey provides a large dataset of low-resolution spectra from thousands of galaxies in the GOODS north and south fields. One important subset of objects in these data is emission-line galaxies (ELGs), and we have investigated several different methods aimed at systematically selecting these galaxies. Here, we present a new methodology and results of a search for these ELGs in the PEARS observations of the Hubble Ultra Deep Field (HUDF) using a 2D detection method that utilizes the observation that many emission lines originate from clumpy knots within galaxies. This 2D line-finding method proves to be useful in detecting emission lines from compact knots within galaxies that might not otherwise be detected using more traditional 1D line-finding techniques.
- ID:
- ivo://CDS.VizieR/J/AJ/141/64
- Title:
- PEARS emission-line galaxies spectroscopy
- Short Name:
- J/AJ/141/64
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectroscopy of 76 emission-line galaxies (ELGs) in Chandra Deep Field South taken with the LDSS3 spectrograph on the Magellan Telescope. These galaxies are selected because they have emission lines with the Advanced Camera for Surveys (ACS) grism data in the Hubble Space Telescope Probing Evolution and Reionization Spectroscopically (PEARS) grism Survey. The ACS grism spectra cover the wavelength range 6000-9700{AA} and most PEARS grism redshifts are based on a single emission line + photometric redshifts from broadband colors; the Magellan spectra cover a wavelength range from 4000{AA} to 9000{AA} and provide a check on redshifts derived from PEARS data.
- ID:
- ivo://CDS.VizieR/J/ApJ/676/184
- Title:
- Peculiar motion away from the Local Void
- Short Name:
- J/ApJ/676/184
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The peculiar velocity of the Local Group of galaxies manifested in the cosmic microwave background dipole is found to decompose into three dominant components. The three components are clearly separated because they arise on distinct spatial scales and are fortuitously almost orthogonal in their influences. The nearest, which is distinguished by a velocity discontinuity at ~7Mpc, arises from the evacuation of the Local Void. We lie in the Local Sheet that bounds the void. Random motions within the Local Sheet are small, and we advocate a reference frame with respect to the Local Sheet in preference to the Local Group.
- ID:
- ivo://CDS.VizieR/J/MNRAS/445/2677
- Title:
- Peculiar velocities in 6dFGS
- Short Name:
- J/MNRAS/445/2677
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive peculiar velocities for the 6dF Galaxy Survey (6dFGS) and describe the velocity field of the nearby (z<0.055) Southern hemisphere. The survey comprises 8885 galaxies for which we have previously reported Fundamental Plane data. We obtain peculiar velocity probability distributions for the redshift-space positions of each of these galaxies using a Bayesian approach. Accounting for selection bias, we find that the logarithmic distance uncertainty is 0.11 dex, corresponding to 26 per cent in linear distance. We use adaptive kernel smoothing to map the observed 6dFGS velocity field out to cz~16000km/s, and compare this to the predicted velocity fields from the PSCz Survey and the 2MASS Redshift Survey. We find a better fit to the PSCz prediction, although the reduced {chi}^2^ for the whole sample is approximately unity for both comparisons. This means that, within the observational uncertainties due to redshift-independent distance errors, observed galaxy velocities and those predicted by the linear approximation from the density field agree. However, we find peculiar velocities that are systematically more positive than model predictions in the direction of the Shapley and Vela superclusters, and systematically more negative than model predictions in the direction of the Pisces-Cetus Supercluster, suggesting contributions from volumes not covered by the models.
- ID:
- ivo://CDS.VizieR/J/other/Ap/49.450
- Title:
- Peculiar velocities of 2MFGC spirals
- Short Name:
- J/other/Ap/49.45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 2MFGC catalog we have used contains 18020 galaxies selected from among the extended objects in the 2MASS infrared sky survey as having apparent ratios of the axes b/a<0.3. Most of them are spiral galaxies of later morphological types whose disks are seen almost edge-on. The individual distances to the 2724 2MFGC galaxies with known rotation velocities and radial velocities are determined using a multiparameter infrared Tully-Fisher relation. A list of the distances and peculiar velocities of these galaxies is presented. The collective motion of the 2MFGC galaxies relative to the cosmic microwave background is characterized by a velocity V=199+/-37km/s in the direction l=304+/-11, b=-8+/-8 . Our list is currently the most representative and uniform sample for analyzing non-Hubble motions of galaxies on a scale of ~100Mpc.
- ID:
- ivo://CDS.VizieR/J/A+A/658/A188
- Title:
- PHANGS-MUSE sample HII regions catalog
- Short Name:
- J/A+A/658/A188
- Date:
- 02 Mar 2022 06:10:18
- Publisher:
- CDS
- Description:
- We use an unprecedented sample of about 23000 HII regions detected at an average physical resolution of 67pc in the PHANGS-MUSE sample to study the extragalactic HII region H{alpha} luminosity function (LF). Our observations probe the star-forming disk of 19 nearby spiral galaxies with low inclination and located close to the star formation main sequence at z=0. The mean LF slope in our sample is =1.73 with a {sigma} of 0.15. We find that {alpha} decreases with the galaxy's star formation rate surface density {SIGMA}_SFR_ and argue that this is driven by an enhanced clustering of young stars at high gas surface densities. Looking at the HII regions within single galaxies we find that no significant variations occur between the LF of the inner and outer part of the star-forming disk, whereas the LF in the spiral arm areas is shallower than in the inter-arm areas for six out of the 13 galaxies with clearly visible spiral arms. We attribute these variations to the spiral arms increasing the molecular clouds arm-inter-arm mass contrast and find suggestive evidence that they are more evident for galaxies with stronger spiral arms. Furthermore, we find systematic variations in {alpha} between samples of HII regions with high and low ionization parameter q and argue that they are driven by the aging of HII regions.
- ID:
- ivo://CDS.VizieR/J/ApJ/802/127
- Title:
- PHAT stellar cluster survey. II. AP catalog
- Short Name:
- J/ApJ/802/127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We construct a stellar cluster catalog for the Panchromatic Hubble Andromeda Treasury (PHAT) survey using image classifications collected from the Andromeda Project (AP) citizen science website. We identify 2753 clusters and 2270 background galaxies within ~0.5deg^2^ of PHAT imaging searched, or ~400kpc^2^ in deprojected area at the distance of the Andromeda Galaxy (M31). These identifications result from 1.82million classifications of ~20000 individual images (totaling ~7gigapixels) by tens of thousands of volunteers. We show that our crowd-sourced approach, which collects >80 classifications per image, provides a robust, repeatable method of cluster identification. The high spatial resolution Hubble Space Telescope images resolve individual stars in each cluster and are instrumental in the factor of ~6 increase in the number of clusters known within the survey footprint. We measure integrated photometry in six filter passbands, ranging from the near-UV to the near-IR. PHAT clusters span a range of ~8 magnitudes in F475W (g-band) luminosity, equivalent to ~4 decades in cluster mass. We perform catalog completeness analysis using >3000 synthetic cluster simulations to determine robust detection limits and demonstrate that the catalog is 50% complete down to ~500M_{sun}_ for ages <100Myr. We include catalogs of clusters, background galaxies, remaining unselected candidates, and synthetic cluster simulations, making all information publicly available to the community. The catalog published here serves as the definitive base data product for PHAT cluster science, providing a census of star clusters in an L^*^ spiral galaxy with unmatched sensitivity and quality.
- ID:
- ivo://CDS.VizieR/J/ApJ/752/95
- Title:
- PHAT stellar cluster survey. I. Year 1
- Short Name:
- J/ApJ/752/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Panchromatic Hubble Andromeda Treasury (PHAT) survey is an ongoing Hubble Space Telescope (HST) multi-cycle program to obtain high spatial resolution imaging of one-third of the M31 disk at ultraviolet through near-infrared wavelengths. In this paper, we present the first installment of the PHAT stellar cluster catalog. When completed, the PHAT cluster catalog will be among the largest and most comprehensive surveys of resolved star clusters in any galaxy. The exquisite spatial resolution achieved with HST has allowed us to identify hundreds of new clusters that were previously inaccessible with existing ground-based surveys. We identify 601 clusters in the Year 1 sample, representing more than a factor of four increase over previous catalogs within the current survey area (390 arcmin^2^). This work presents results derived from the first ~25% of the survey data; we estimate that the final sample will include ~2500 clusters. For the Year 1 objects, we present a catalog with positions, radii, and six-band integrated photometry. Along with a general characterization of the cluster luminosities and colors, we discuss the cluster luminosity function, the cluster size distributions, and highlight a number of individually interesting clusters found in the Year 1 search.
- ID:
- ivo://CDS.VizieR/J/MNRAS/451/724
- Title:
- PHAT. XIII. M31 Cepheid P-L relation
- Short Name:
- J/MNRAS/451/724
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using Hubble Space Telescope Advanced Camera for Surveys (HST/ACS) and Wide Field Camera 3 (WFC3) observations from the Panchromatic Hubble Andromeda Treasury (PHAT), we present new period-luminosity (P-L) relations for Cepheid variables in M31. Cepheids from several ground-based studies are identified in the PHAT photometry to derive new P-L and Wesenheit P-L relations in the near infrared and visual filters. We derive a distance modulus to M31 of 24.51+/-0.08 in the IR bands and 24.32+/-0.09 in the visual bands, including the first P-L relations in the F_475W_ and F_814W_ filters for M31. Our derived visual and IR distance moduli disagree at slightly more than a 1{sigma} level. Differences in the P-L relations between ground-based and HST observations are investigated for a subset of Cepheids. We find a significant discrepancy between ground-based and HST P-L relations with the same Cepheids, suggesting adverse effects from photometric contamination in ground-based Cepheid observations. Additionally, a statistically significant radial trend in the P-L relation is found which does not appear to be explained by metallicity.
