- ID:
- ivo://CDS.VizieR/J/ApJ/449/527
- Title:
- Galaxies in the zone of avoidance
- Short Name:
- J/ApJ/449/527
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have selected a sample of 876 galaxy candidates from the IRAS Point Source Catalog in the region of 2h<RA<10h and 0deg<DE<36deg, which crosses the Galactic anticenter part of the Zone of Avoidance (ZOA) and includes most of the highly obscured Orion-Taurus complex region. We have identified galaxies among the candidate sources by attempting to detect the 21cm H I line of those sources which were not known to be galaxies at the beginning of the survey. In this manner, we constructed a galaxy sample which is largely free from Galactic reddening. Of the 272 observed candidates, 89 were detected in the H I line up to a heliocentric velocity of v_h_~16,000km/s. The resulting galaxy sample of 717 galaxies is fairly complete (within about 10%) and uniform (within about 4%) in the part of the survey area 10deg away from the Galactic plane and for velocities up to at least 9000km/s. This provides, for the first time, a largely unbiased view on the large-scale structures in much of the survey area. Our main results are the following: (1) Several large voids are identified. In particular, a void between RA~3h and 4h, up to v_h_~6000km/s, separates the Pisces-Perseus supercluster at RA<3h from structures at RA>4h; and a "nearby void" occupies most of our survey area and reaches out to a redshift of nearly 3000km/s. (2) We found no nearby galaxy concentration that could significantly contribute to the "Local Velocity Anomaly" (LVA), but a general excess of galaxies around v_h_~5000km/s in the survey area. (3) The contrast between the "Great Wall" at v_h_~8500km/s and the void in front of it appears to gradually diffuse out after it enters the Zone of Avoidance from the northern Galactic hemisphere. (4) Our data combined with other galaxy surveys in or near the Galactic anticenter part of the ZOA suggest that the main ridge of the Pisces-Perseus supercluster does also not extend to Abell 569, a cluster in the northern Galactic hemisphere, and that the simple gravitational model consisting of the Local Void of Tully & Fisher, our nearby void, and Puppis and Fornax-Eridanus clusters would predict a LVA whose direction is probably too far away from that derived from observations.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/107/521
- Title:
- Galaxies redshifts, 210<l<360, |b|<15
- Short Name:
- J/ApJS/107/521
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out a redshift survey of an IRAS flux-limited (f_60_>0.6) galaxy sample behind the southern Milky Way, 210{deg}<l<360{deg} at |b|<15{deg}. The survey includes redshifts for 951 galaxies, ~500 of which are new. Of these 951 galaxies, 462 are in the zone 5{deg}<b<15{deg} and 353 are in the zone -15{deg}<b<-5{deg}. Though the innermost region of the Milky Way (|b|=5{deg}) remains opaque except in the longitude near 240, the detected galaxies show a high degree of completeness (~70%) in the zones 5{deg}<b<15{deg} and -15{deg}<b<-5{deg}. The cone diagrams exhibiting the detailed distribution of IRAS galaxies in the region 210{deg}<l<360{deg}, |b|<15{deg} shows two clusters in the Puppis region (l=240{deg}, b=-7{deg}, v=2400km/s; l=245{deg}, b=-5{deg}, v=7500km/s), the A3627 cluster (l=325{deg}, b=-7{deg}; v=4500km/s), the S4 cluster (l=280{deg}, b=7{deg}; v=5500km/s), and a possible void at l=245{deg}, v=3000km/s. The region 270{deg}<l<350{deg} is dominated by overdensity of galaxies representing the extension of the Hydra-Centaurus complex in the positive latitudes and the Pavo-Indus complex in the negative latitudes. A velocity histogram of galaxies in the GA region 290{deg}<l<350{deg}, |b|<15{deg}. reveals a substantial overdensity of galaxies in the velocity range 2400-5000km/s. The centroid of this overdensity is located at 4000km/s. The broad increased density of galaxies seen in our data corresponds with the distant concentration seen at 4500km/s in the supergalactic plane survey that covers the same longitude range like ours in l, but a larger range in latitude b (-30{deg} to -10{deg} and +10{deg} to +45{deg}). This lends support to the idea that the overdensity extends all the way from the Centaurus-Hydra complex (l=302{deg}, b=+22{deg}) in the north to the major concentration of the Pavo-Indus supercluster (l=332{deg}, b=-24{deg}) in the south, through the Milky Way. We conclude that the peak of the overdensity responsible for the peculiar velocity field in the local region is possibly situated in the Milky Way itself.
- ID:
- ivo://CDS.VizieR/J/ApJ/872/95
- Title:
- GALEX and Gaia data for APOGEE red clump stars
- Short Name:
- J/ApJ/872/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Although core helium-burning red clump (RC) stars are faint at ultraviolet wavelengths, their ultraviolet (UV)-optical color is a unique and accessible probe of their physical properties. Using data from the Galaxy Evolution Explorer All Sky Imaging Survey (GALEX AIS), Gaia Data Release 2, and the Sloan Digital Sky Survey Apache Point Observatory Galactic Evolution Experiment (APOGEE) DR14 survey, we find that spectroscopic metallicity is strongly correlated with the location of an RC star in the UV-optical color-magnitude diagram. The RC has a wide spread in (NUV-G)_0_ color of over 4mag compared to a 0.7mag range in (G_BP_-G_RP_)_0_. We propose a photometric, dust-corrected, UV-optical (NUV-G)_0_ color-metallicity [Fe/H] relation using a sample of 5175 RC stars from APOGEE. We show that this relation has a scatter of 0.16dex and is easier to obtain for large, wide-field samples than for spectroscopic metallicities. Importantly, the effect may be comparable to the spread in RC color attributed to extinction in other studies.
- ID:
- ivo://CDS.VizieR/J/A+A/654/A150
- Title:
- Gas and young stars in CMa OB1 assoc.
- Short Name:
- J/A+A/654/A150
- Date:
- 21 Mar 2022 09:18:01
- Publisher:
- CDS
- Description:
- The relationship between young stellar clusters and their respective parental molecular clouds remains an open issue. Recent inquiries consider the similarities between substructures of clouds and clusters and whether they are a coincidence or, rather, an indication of a physical relationship. To address these issues, we studied the CMa OB1/R1 region, which shows evidence of a complex star formation history. We obtained molecular cloud mapping with the IRAM-30 metre telescope to reveal the physical conditions of an unexplored side of the CMa region with the aim of comparing the morphology of the clouds to the distribution of young stellar objects (YSOs). We also studied the cloud kinematics in pursuit of gradients and jet signatures that could trace different star formation scenarios. The YSOs were selected on the basis of astrometric data from Gaia EDR3 that characterize the moving groups. The distance of 1099_-24_^+25^pc was obtained for the sample, based on the mean error-weighted parallax. Optical and near-infrared photometry was used to verify the evolutionary status and circumstellar characteristics of the YSOs. Among the selected candidates, we found 40 members associated with the cloud: 1 Class I, 11 Class II, and 28 Class III objects. Comparing the spatial distribution of the stellar population with the cores revealed by the ^13^CO map, we verified that peaks of emission coincide with the position of YSOs, confirming the association of these objects to their dense natal gas. Our observations support the large-scale scenario of the CMa shell-like structure formation as a relic of successive supernova events.
- ID:
- ivo://CDS.VizieR/J/A+A/422/941
- Title:
- Gas content in 1038 interacting galaxies
- Short Name:
- J/A+A/422/941
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A study of the gas content in 1038 interacting galaxies, essentially selected from Arp (<VII/74>), Arp and Madore (<VII/170>), Vorontsov-Velyaminov (<VII/236>) catalogues and some of the published literature, is presented here. The data on the interstellar medium have been extracted from a number of sources in the literature and compared with a sample of 1916 normal galaxies. The mean values for each of the different ISM tracers (FIR, 21cm, CO lines, X-ray) have been estimated by means of survival analysis techniques, in order to take into account the presence of upper limits.
- ID:
- ivo://CDS.VizieR/J/A+A/627/A132
- Title:
- GAS II. UV luminosity functions & InfraRed eXcess
- Short Name:
- J/A+A/627/A132
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Dust is a crucial component of the interstellar medium of galaxies. The presence of dust strongly affects the light produced by stars within a galaxy. As these photons are our main information vector to explore the stellar mass assembly and therefore understand a galaxy's evolution, modeling the luminous properties of galaxies and taking into account the impact of the dust is a fundamental challenge for semi-analytical models. We present the complete prescription of dust attenuation implemented in the new semi-analytical model (SAM): G.A.S. . This model is based on a two-phase medium originating from a physically motivated turbulent model of gas structuring (G.A.S. I paper). Dust impact is treated by taking into account three dust components: Polycyclic Aromatic Hydrocarbons, Very Small Grains, and Big Grains. All three components evolve in both a diffuse and a fragmented/dense gas phase. Each phase has its own stars, dust content and geometry. Dust content evolves according to the metallicity of it associated phase. The G.A.S. model is used to predict both the UV and the IR luminosity functions from z=9.0 to z=0.1. Our two-phase ISM prescription catches very well the evolution of UV and IR luminosity functions. We note a small overproduction of the IR luminosity at low redshift (z<0.5). We also focus on the Infrared-Excess (IRX) and explore its dependency with the stellar mass, UV slope, stellar age, metallicity and slope of the attenuation curves. Our model predicts large scatters for relations based on IRX, especially for the IRX- relation. Our analysis reveals that the slope of the attenuation curve is more driven by absolute attenuation in the FUV band than by disk inclination.We confirm that the age of the stellar population and the slope of the attenuation curve can both shift galaxies below the fiducial star-birth relation in the IRX- diagram. Main results presented in this paper (e.g. luminosity functions) and in the two other associated G.A.S. papers are stored and available in the GALAKSIENN library through the ZENODO platform.
- ID:
- ivo://CDS.VizieR/J/ApJ/886/L14
- Title:
- Gemini/FLAMINGOS-2 NIR spectra of V1047 Cen
- Short Name:
- J/ApJ/886/L14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Fourteen years after its eruption as a classical nova (CN), V1047 Cen (Nova Cen 2005) began an unusual re-brightening in 2019 April. The amplitude of the brightening suggests that this is a dwarf nova (DN) eruption in a CN system. Very few CNe have had DN eruptions within decades of the main CN outburst. The 14yr separating the CN and DN eruptions of V1047 Cen is the shortest of all instances recorded thus far. Explaining this rapid succession of CN and DN outbursts in V1047 Cen may be challenging within the framework of standard theories for DN outbursts. Following a CN eruption, the mass accretion rate is believed to remain high (dM/dt~10^-8^M_{sun}_/yr) for a few centuries, due to the irradiation of the secondary star by the still-hot surface of the white dwarf. Thus a DN eruption is not expected to occur during this high mass accretion phase as DN outbursts, which result from thermal instabilities in the accretion disk, and arise during a regime of low mass accretion rate (dM/dt~10^-10^M_{sun}_/yr). Here we present near-infrared spectroscopy to show that the present outburst is most likely a DN eruption, and discuss the possible reasons for its early occurrence. Even if the present re-brightening is later shown to be due to a cause other than a DN outburst, the present study provides invaluable documentation of this unusual event.
- ID:
- ivo://CDS.VizieR/J/ApJ/873/35
- Title:
- Gemini GNIRS NIR spectroscopy of 50 QSOs at z>~5.7
- Short Name:
- J/ApJ/873/35
- Date:
- 19 Jan 2022 09:09:09
- Publisher:
- CDS
- Description:
- We report initial results from a large Gemini program to observe z>~5.7 quasars with GNIRS near-IR spectroscopy. Our sample includes 50 quasars with simultaneous ~0.85-2.5{mu}m spectra covering the rest-frame ultraviolet and major broad emission lines from Ly{alpha} to MgII. We present spectral measurements for these quasars and compare with their lower redshift counterparts at z=1.5-2.3. We find that when quasar luminosity is matched, there are no significant differences between the rest-UV spectra of z>~5.7 quasars and the low-z comparison sample. High-z quasars have similar continuum and emission line properties and occupy the same region in the black hole mass and luminosity space as the comparison sample, accreting at an average Eddington ratio of ~0.3. There is no evidence for super-Eddington accretion or hypermassive (>10^10^M_{sun}_) black holes within our sample. We find a mild excess of quasars with weak CIV lines relative to the control sample. Our results, corroborating earlier studies but with better statistics, demonstrate that these high-z quasars are already mature systems of accreting supermassive black holes operating with the same physical mechanisms as those at lower redshifts.
- ID:
- ivo://CDS.VizieR/J/ApJ/858/102
- Title:
- Gemini/NIFS and HST obs. of the galaxy M59-UCD3
- Short Name:
- J/ApJ/858/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We examine the internal properties of the most massive ultracompact dwarf galaxy (UCD), M59-UCD3, by combining adaptive-optics-assisted near-IR integral field spectroscopy from Gemini/NIFS and Hubble Space Telescope (HST) imaging. We use the multiband HST imaging to create a mass model that suggests and accounts for the presence of multiple stellar populations and structural components. We combine these mass models with kinematics measurements from Gemini/NIFS to find a best-fit stellar mass-to-light ratio (M/L) and black hole (BH) mass using Jeans anisotropic models (JAMs), axisymmetric Schwarzschild models, and triaxial Schwarzschild models. The best-fit parameters in the JAM and axisymmetric Schwarzschild models have BHs between 2.5 and 5.9 million solar masses. The triaxial Schwarzschild models point toward a similar BH mass but show a minimum {chi}^2^ at a BH mass of ~0. Models with a BH in all three techniques provide better fits to the central V_rms_ profiles, and thus we estimate the BH mass to be 4.2_-1.7_^+2.1^x10^6^M_{sun}_ (estimated 1{sigma} uncertainties). We also present deep radio imaging of M59-UCD3 and two other UCDs in Virgo with dynamical BH mass measurements, and we compare these to X-ray measurements to check for consistency with the fundamental plane of BH accretion. We detect faint radio emission in M59cO but find only upper limits for M60-UCD1 and M59-UCD3 despite X-ray detections in both these sources. The BH mass and nuclear light profile of M59-UCD3 suggest that it is the tidally stripped remnant of a ~10^9^-10^10^M_{sun}_ galaxy.
- ID:
- ivo://CDS.VizieR/J/AJ/155/226
- Title:
- Gemini Planet Imager spectra of HR 8799 c/d/e
- Short Name:
- J/AJ/155/226
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explore Karhunen Loeve Image Projection (KLIP) forward modeling spectral extraction on Gemini Planet Imager coronagraphic data of HR 8799, using PyKLIP, and show algorithm stability with varying KLIP parameters. We report new and re-reduced spectrophotometry of HR 8799 c, d, and e in the H and K bands. We discuss a strategy for choosing optimal KLIP PSF subtraction parameters by injecting simulated sources and recovering them over a range of parameters. The K1/K2 spectra for HR 8799 c and d are similar to previously published results from the same data set. We also present a K-band spectrum of HR 8799 e for the first time and show that our H-band spectra agree well with previously published spectra from the VLT/SPHERE instrument. We show that HR 8799 c and d show significant differences in their H and K spectra, but do not find any conclusive differences between d and e, nor between c and e, likely due to large error bars in the recovered spectrum of e. Compared to M-, L-, and T-type field brown dwarfs, all three planets are most consistent with mid- and late-L spectral types. All objects are consistent with low gravity, but a lack of standard spectra for low gravity limit the ability to fit the best spectral type. We discuss how dedicated modeling efforts can better fit HR 8799 planets' near-IR flux, as well as how differences between the properties of these planets can be further explored.
