- ID:
- ivo://CDS.VizieR/J/ApJ/692/422
- Title:
- MAMBO observations of SWIRE sources
- Short Name:
- J/ApJ/692/422
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on-off pointed MAMBO observations at 1.2mm of 61 Spitzer-selected star-forming galaxies from the Spitzer Wide Area Infrared Extragalactic Legacy survey (SWIRE). The sources are selected on the basis of bright 24um fluxes (F24um>0.4mJy) and of stellar dominated near-infrared spectral energy distributions in order to favor z~2 starburst galaxies. The average 1.2mm flux for the whole sample is 1.5+/-0.2mJy. Our analysis focuses on 29 sources in the Lockman Hole field where the average 1.2mm flux (1.9+/-0.3mJy) is higher than in other fields (1.1+/-0.2mJy). The analysis of the multiwavelength spectral energy distributions indicates that these sources are starburst galaxies with far-infrared luminosities from 10^12^ to 10^13.3^L_{sun}_, and stellar masses of ~0.2-6x10^11^M_{sun}_. Compared to submillimeter selected galaxies (SMGs), the SWIRE-MAMBO sources are among those with the largest 24um/1.2mm flux ratios. The origin of such large ratios is investigated by comparing the average mid-infrared spectra and the stacked far-infrared spectral energy distributions of the SWIRE-MAMBO sources and of SMGs.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/131/2478
- Title:
- M31 and M33 UBVRI photometry
- Short Name:
- J/AJ/131/2478
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UBVRI photometry obtained from Mosaic images of M31 and M33 using the Kitt Peak National Observatory 4m telescope. We describe our data reduction and automated photometry techniques in some detail, as we will shortly perform a similar analysis of other Local Group galaxies. The present study covered 2.2deg^2^ along the major axis of M31 and 0.8deg^2^ on M33, chosen so as to include all of the regions currently active in forming massive stars. We calibrated our data using photometry from the Lowell 1.1m telescope, and this external method resulted in millimagnitude differences in the photometry of overlapping fields, providing some assurance that our photometry is reliable. The final catalog contains 371781 and 146622 stars in M31 and M33, respectively, where every star has a counterpart in (at least) the B, V, and R passbands. Our survey goes deep enough to achieve 1%-2% photometry at 21mag (corresponding to stars more massive than 20M_{sun}_) and achieves <10% errors at ~U ~B ~V ~R ~I 23mag.
- ID:
- ivo://CDS.VizieR/J/AJ/119/1760
- Title:
- M54 and Sgr dSph VI photometry
- Short Name:
- J/AJ/119/1760
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep VI-band photometry of the globular cluster M54, a nearby field in the Sagittarius dwarf galaxy, and a control field. The color-magnitude diagrams reach well below the oldest main-sequence turnoffs, thus enabling an analysis of the galaxy's age-metallicity relation with unprecedented clarity. We also study the variable stars in the direction of M54. From 67 RR Lyrae variables, we confirm and improve on our previous estimates of the cluster horizontal branch magnitude, foreground reddening, and horizontal branch morphology. These values are used in determining the ages of M54 and the Sagittarius field populations. We confirm our previous result that M54 is the same age as Galactic globular clusters of similar metallicity.
2174. MaNGA catalog, DR15
- ID:
- ivo://CDS.VizieR/J/AJ/154/86
- Title:
- MaNGA catalog, DR15
- Short Name:
- J/AJ/154/86
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the sample design for the SDSS-IV MaNGA survey and present the final properties of the main samples along with important considerations for using these samples for science. Our target selection criteria were developed while simultaneously optimizing the size distribution of the MaNGA integral field units (IFUs), the IFU allocation strategy, and the target density to produce a survey defined in terms of maximizing signal-to-noise ratio, spatial resolution, and sample size. Our selection strategy makes use of redshift limits that only depend on i-band absolute magnitude (M_i_), or, for a small subset of our sample, M i and color (NUV-i). Such a strategy ensures that all galaxies span the same range in angular size irrespective of luminosity and are therefore covered evenly by the adopted range of IFU sizes. We define three samples: the Primary and Secondary samples are selected to have a flat number density with respect to M_i_ and are targeted to have spectroscopic coverage to 1.5 and 2.5 effective radii (Re), respectively. The Color-Enhanced supplement increases the number of galaxies in the low-density regions of color-magnitude space by extending the redshift limits of the Primary sample in the appropriate color bins. The samples cover the stellar mass range 5x10^8^<=M*<=3x10^11^M_{sun}/h^2^ and are sampled at median physical resolutions of 1.37 and 2.5kpc for the Primary and Secondary samples, respectively. We provide weights that will statistically correct for our luminosity and color-dependent selection function and IFU allocation strategy, thus correcting the observed sample to a volume-limited sample.
- ID:
- ivo://CDS.VizieR/J/MNRAS/476/1765
- Title:
- MaNGA E and S galaxies properties
- Short Name:
- J/MNRAS/476/1765
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We perform full spectrum fitting stellar population analysis and Jeans Anisotropic modelling of the stellar kinematics for about 2000 early-type galaxies (ETGs) and spiral galaxies from the MaNGA DR14 sample. Galaxies with different morphologies are found to be located on a remarkably tight mass plane which is close to the prediction of the virial theorem, extending previous results for ETGs. By examining an inclined projection ('the mass-size' plane), we find that spiral and early-type galaxies occupy different regions on the plane, and their stellar population properties (i.e. age, metallicity, and stellar mass-to-light ratio) vary systematically along roughly the direction of velocity dispersion, which is a proxy for the bulge fraction. Galaxies with higher velocity dispersions have typically older ages, larger stellar mass-to-light ratios and are more metal rich, which indicates that galaxies increase their bulge fractions as their stellar populations age and become enriched chemically. The age and stellar mass-to-light ratio gradients for low-mass galaxies in our sample tend to be positive (centre<outer), while the gradients for most massive galaxies are negative. The metallicity gradients show a clear peak around velocity dispersion log_10_{sigma}_e_~=2.0, which corresponds to the critical mass ~3x10^10^M_{sun}_ of the break in the mass-size relation. Spiral galaxies with large mass and size have the steepest gradients, while the most massive ETGs, especially above the critical mass M_crit_>=2x 10^11^M_{sun}_, where slow rotator ETGs start dominating, have much flatter gradients. This may be due to differences in their evolution histories, e.g. mergers.
- ID:
- ivo://CDS.VizieR/J/ApJ/891/85
- Title:
- Manganese abundances in GC & dSph galaxies
- Short Name:
- J/ApJ/891/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Manganese abundances are sensitive probes of the progenitors of TypeIa supernovae (SNe Ia). In this work, we present a catalog of manganese abundances in dwarf spheroidal satellites of the Milky Way, measured using medium-resolution spectroscopy. Using a simple chemical evolution model, we infer the manganese yield of SNe Ia in the Sculptor dwarf spheroidal galaxy (dSph) and compare to theoretical yields. The sub-solar yield from SNIa ([Mn/Fe]_Ia_=-0.30_-0.03_^+0.03^ at [Fe/H]=-1.5dex, with negligible dependence on metallicity) implies that sub-Chandrasekhar-mass (sub-MCh) white dwarf progenitors are the dominant channel of SNe Ia at early times in this galaxy, although some fraction (>~20%) of M_Ch_ Type Ia or Type Iax SNe are still needed to produce the observed yield. First-order corrections for deviations from local thermodynamic equilibrium increase the inferred [Mn/Fe]_Ia_ by as much as ~0.3dex. However, our results also suggest that the nucleosynthetic source of SNe Ia may depend on environment. In particular, we find that dSphs with extended star formation histories (Leo I, Fornax dSphs) appear to have higher [Mn/Fe] at a given metallicity than galaxies with early bursts of star formation (Sculptor dSph), suggesting that M_Ch_ progenitors may become the dominant channel of SNe Ia at later times in a galaxy's chemical evolution.
- ID:
- ivo://CDS.VizieR/J/ApJ/903/52
- Title:
- MaNGA; parameters of 668 galaxies
- Short Name:
- J/ApJ/903/52
- Date:
- 15 Mar 2022
- Publisher:
- CDS
- Description:
- The search for new global scaling relations linking the physical properties of galaxies has a fundamental interest. Furthermore, their recovery from spatially resolved relations has been in the spotlight of integral field spectroscopy (IFS). In this study, we investigate the existence of global and local relations between stellar age (Age*) and gas-phase metallicity (Zg). To this aim, we analyze IFS data for a sample of 736 star-forming disk galaxies from the MaNGA survey. We report a positive correlation between the global Zg and D(4000) (an indicator of stellar age), with a slope that decreases with increasing galaxy mass. Locally, a similar trend is found when analyzing the Zg and D(4000) of the star-forming regions, as well as the residuals resulting from removing the radial gradients of both parameters. The local laws have systematically smaller slopes than the global one. We ascribe this difference to random errors that cause the true slope of the Age*-Zg relation to be systematically underestimated when performing a least-squares fitting. The explored relation is intimately linked with the already known relation between gas metallicity and star formation rate at fixed mass, both presenting a common physical origin.
- ID:
- ivo://CDS.VizieR/J/MNRAS/508/1084
- Title:
- MaNGA star-forming galaxies
- Short Name:
- J/MNRAS/508/1084
- Date:
- 19 Jan 2022 00:58:55
- Publisher:
- CDS
- Description:
- We investigate radiation hardness within a representative sample of 67 nearby (0.02<~z<~0.06) star-forming (SF) galaxies using the integral field spectroscopic data from the MaNGA survey. The softness parameter {eta}=(O^+^/O^2+^)/(S^+^/S^2+^) is sensitive to the spectral energy distribution of the ionizing radiation. We study {eta} via the observable quantity {eta}'(=([OII]/[OIII])/([SII][SIII])). We analyze the relation between radiation hardness (traced by {eta} and {eta}') and diagnostics sensitive to gas-phase metallicity, electron temperature, density, ionization parameter, effective temperature, and age of ionizing populations. It is evident that low metallicity is accompanied by low log{eta}', i.e. hard radiation field. No direct relation is found between radiation hardness and other nebular parameters though such relations cannot be ruled out. We provide empirical relations between log{eta} and strong emission line ratios N2, O3N2, and Ar3O3, which will allow future studies of radiation hardness in SF galaxies where weak auroral lines are undetected. We compare the variation of [OIII]/[OII] and [SIII]/[SII] for MaNGA data with SF galaxies and HII regions within spiral galaxies from literature and find that the similarity and differences between different data set are mainly due to the metallicity. We find that predictions from photoionization models considering young and evolved stellar populations as ionizing sources in good agreement with the MaNGA data. This comparison also suggests that hard radiation fields from hot and old low-mass stars within or around SF regions might significantly contribute to the observed {eta} values.
- ID:
- ivo://CDS.VizieR/J/A+A/629/A1
- Title:
- Mapping the stellar age of the Milky Way
- Short Name:
- J/A+A/629/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The bulge represents the best compromise between old and massive Galactic component, and as such its study is a valuable opportunity to understand how the bulk of the Milky Way formed and evolved. In addition, being the only bulge in which we can individually resolve stars in all evolutionary sequences, the properties of its stellar content provide crucial insights on the formation of bulges at large. We aim at providing a detailed and comprehensive census of the Milky Way bulge stellar populations by producing deep and accurate photometric catalogs of the inner ~300 sqdeg of the Galaxy. We perform DAOPHOT/ALLFRAME PSF-fitting photometry of multi-epochs J and Ks images provided by the VVV survey to obtain deep photometric catalogs. Artificial star experiments have been conducted on all images to properly assess the completeness and the accuracy of the photometric measurements. We present a photometric database containing nearly 600 million stars across the bulge area surveyed by the VVV. Through the comparison of derived color-magnitude diagrams of selected fields representative of different levels of extinction and crowding, we show the quality, completeness and depth of the new catalogs. With the exception of the fields located along the plane, this new photometry samples stars down to ~1-2mag below the MS-TO with unprecedented accuracy. To demonstrate the tremendous potential inherent to this new dataset, we give few examples of possible applications such as: i) star counts studies through the dataset completeness map; ii) surface brightness map; and iii) cross-correlation with Gaia DR2. The database presented here represents an invaluable collection for the whole community, and we encourage its exploitation. The photometric catalogs including completeness information are publicly available through the ESO Science Archive.
- ID:
- ivo://CDS.VizieR/J/MNRAS/459/2262
- Title:
- Maps of dust distribution in M31 bulge
- Short Name:
- J/MNRAS/459/2262
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We map the dust distribution in the central 180" (~680pc) region of the M31 bulge, based on HST WFC3 and ACS observations in ten bands from near-ultraviolet (2700{AA}) to near-infrared (1.5-micron). This large wavelength coverage gives us great leverage to detect not only dense dusty clumps, but also diffuse dusty molecular gas. We fit a pixel-by-pixel spectral energy distributions to construct a high-dynamic-range extinction map with unparalleled angular resolution (~0.5", i.e., ~2pc) and sensitivity (the extinction uncertainty, delta A_V_~0.05). In particular, the data allow to directly fit the fractions of starlight obscured by individual dusty clumps, and hence their radial distances in the bulge. Most of these clumps seem to be located in a thin plane, which is tilted with respect to the M31 disk and appears face-on. We convert the extinction map into a dust mass surface density map and compare it with that derived from the dust emission as observed by Herschel. The dust masses in these two maps are consistent with each other, except in the low-extinction regions, where the mass inferred from the extinction tends to be underestimated. Further, we use simulations to show that our method can be used to measure the masses of dusty clumps in Virgo cluster early-type galaxies to an accuracy within a factor of ~2.
