- ID:
- ivo://CDS.VizieR/J/AJ/132/231
- Title:
- MMT hectospec redshift survey of 24um sources
- Short Name:
- J/AJ/132/231
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectroscopic survey using the MMT Hectospec fiber spectrograph of 24um sources selected with the Spitzer Space Telescope in the Spitzer First Look Survey. We report 1296 new redshifts for 24um sources, including 599 with f_nu_(24um)>=1mJy. Combined with 291 additional redshifts for sources from the Sloan Digital Sky Survey (SDSS), our observing program was highly efficient and is ~90% complete for i<=21mag and f_nu_(24um)>=1mJy and 35% complete for i<=20.5mag and 0.3mJy<=f_nu_(24um)<1.0mJy. Our Hectospec survey includes 1078 and 168 objects spectroscopically classified as galaxies and QSOs, respectively. Combining the Hectospec and SDSS samples, we find 24 mselected galaxies to zgal<=0.98 and QSOs to zQSO<=3.6, with mean redshifts of <zgal>=0.27 and <zQSO>=1.1. As part of this publication, we include the redshift catalogs and the reduced spectra; these are also available through the NASA/IPAC Infrared Science Archive.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/751/55
- Title:
- MMT hypervelocity star survey. II.
- Short Name:
- J/ApJ/751/55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of five new unbound hypervelocity stars (HVSs) in the outer Milky Way halo. Using a conservative estimate of Galactic escape velocity, our targeted spectroscopic survey has now identified 16 unbound HVSs as well as a comparable number of HVSs ejected on bound trajectories. A Galactic center origin for the HVSs is supported by their unbound velocities, the observed number of unbound stars, their stellar nature, their ejection time distribution, and their Galactic latitude and longitude distribution. Other proposed origins for the unbound HVSs, such as runaway ejections from the disk or dwarf galaxy tidal debris, cannot be reconciled with the observations. An intriguing result is the spatial anisotropy of HVSs on the sky, which possibly reflects an anisotropic potential in the central 10-100pc region of the Galaxy. Further progress requires measurement of the spatial distribution of HVSs over the southern sky. Our survey also identifies seven B supergiants associated with known star-forming galaxies; the absence of B supergiants elsewhere in the survey implies there are no new star-forming galaxies in our survey footprint to a depth of 1-2Mpc.
- ID:
- ivo://CDS.VizieR/J/PASJ/63/S379
- Title:
- MOIRCS Deep Survey deep and wide catalogs
- Short Name:
- J/PASJ/63/S379
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep J-, H-, and Ks-band imaging data of the MOIRCS Deep Survey (MODS), which was carried out with the Multi-Object Infrared Camera and Spectrograph (MOIRCS) mounted on the Subaru Telescope in the GOODS-North region. The data reach 5{sigma} total limiting magnitudes for point sources of J=23.9, H=22.8, and Ks=22.8 (Vega magnitude) over 103 arcmin^2^ (wide field). In 28 arcmin^2^ of the survey area, which is an ultra-deep field of the MODS (deep field), the data reach 5{sigma} depths of J=24.8, H=23.4, and Ks=23.8. The spatial resolutions of the combined images are FWHM~0.6" and ~0.5" for the wide and deep fields in all bands, respectively. Combining the MODS data with the multi-wavelength public data taken with the HST, Spitzer, and other ground-based telescopes in the GOODS field, we constructed a multi-wavelength photometric catalog of Ks-selected sources.
1144. MOIRCS Deep Survey. VII.
- ID:
- ivo://CDS.VizieR/J/PASJ/63/S363
- Title:
- MOIRCS Deep Survey. VII.
- Short Name:
- J/PASJ/63/S363
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigated rest-frame near-infrared (NIR) morphologies of a sample of 139 galaxies with Ms>=1x10^109M_{sun}_ at z=0.8-1.2 in the GOODS-North field using our deep NIR imaging data (MOIRCS Deep Survey, MODS). We focused on Luminous Infrared Galaxies (LIRGs), which dominate a high star formation rate (SFR) density at z~1, in a sample identified by cross-correlating with the Spitzer/MIPS 24mum source catalog. We performed two-dimensional light profile fittings of z~1 galaxies in the Ks-band (rest-frame J-band) with a single-component Sersic model.
- ID:
- ivo://CDS.VizieR/J/ApJ/706/1253
- Title:
- MOJAVE VII. Blazar jet acceleration
- Short Name:
- J/ApJ/706/1253
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We discuss acceleration measurements for a large sample of extragalactic radio jets from the Monitoring Of Jets in Active Galactic Nuclei with VLBA Experiments (MOJAVE) program, which studies the parsec-scale jet structure and kinematics of a complete, flux-density-limited sample of active galactic nuclei (AGNs). Accelerations are measured from the apparent motion of individual jet features or "components" which may represent patterns in the jet flow. We find that significant accelerations are common both parallel and perpendicular to the observed component velocities.
- ID:
- ivo://CDS.VizieR/J/ApJ/798/134
- Title:
- MOJAVE. XII. Acceleration of blazar jets
- Short Name:
- J/ApJ/798/134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the acceleration properties of 329 features in 95 blazar jets from the MOJAVE Very Long Baseline Array program. Nearly half the features and three-quarters of the jets show significant changes in speed and/or direction. In general, apparent speed changes are distinctly larger than changes in direction, indicating that changes in the Lorentz factors of jet features dominate the observed speed changes rather than bends along the line of sight. Observed accelerations tend to increase the speed of features near the jet base, <~10-20pc projected, and decrease their speed at longer distances. The range of apparent speeds at a fixed distance in an individual jet can span a factor of a few, indicating that shock properties and geometry may influence the apparent motions; however, we suggest that the broad trend of jet features increasing their speed near the origin is due to an overall acceleration of the jet flow out to deprojected distances of the order of 10^2^pc, beyond which the flow begins to decelerate or remains nearly constant in speed. We estimate intrinsic rates of change of the Lorentz factors in the galaxy frame of the order of {sdot}{Gamma}/{Gamma}~=10^-3^ to 10^-2^/yr, which can lead to total Lorentz factor changes of a factor of a few on the length scales observed here. Finally, we also find evidence for jet collimation at projected distances of <~10pc in the form of the non-radial motion and bending accelerations that tend to better align features with the inner jet.
- ID:
- ivo://CDS.VizieR/J/ApJS/182/131
- Title:
- Molecular clouds and clumps in the GRS
- Short Name:
- J/ApJS/182/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Boston University-Five College Radio Astronomy Observatory (BU-FCRAO) Galactic Ring Survey (GRS) of ^13^CO J=1->0 emission covers Galactic longitudes 18<l<55.7{deg} and Galactic latitudes |b|<=1{deg}. Using the SEQUOIA array on the FCRAO 14m telescope, the GRS fully sampled the ^13^CO Galactic emission (46" angular resolution on a 22" grid) and achieved a spectral resolution of 0.21km/s. Because the GRS uses ^13^CO, an optically thin tracer, rather than ^12^CO, an optically thick tracer, the GRS allows a much better determination of column density and also a cleaner separation of velocity components along a line of sight. With this homogeneous, fully sampled survey of ^13^CO emission, we have identified 829 molecular clouds and 6124 clumps throughout the inner Galaxy using the CLUMPFIND algorithm. Here we present details of the catalog and a preliminary analysis of the properties of the molecular clouds and their clumps. Moreover, we compare clouds inside and outside of the 5kpc ring and find that clouds within the ring typically have warmer temperatures, higher column densities, larger areas, and more clumps compared with clouds located outside the ring. This is expected if these clouds are actively forming stars. This catalog provides a useful tool for the study of molecular clouds and their embedded young stellar objects.
- ID:
- ivo://CDS.VizieR/J/ApJ/828/59
- Title:
- Molecular clouds in the Milky Way with CO obs.
- Short Name:
- J/ApJ/828/59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galactic plane has been mapped from l=34.75{deg} to 45.25{deg} and b=-5.25{deg} to 5.25{deg} in the CO (J=1-0) emission with the 13.7m telescope of the Purple Mountain Observatory. The unbiased survey covers a large area of 110 square degrees sampled every 30" with a velocity resolution of ~0.2km/s. In this paper, we present the result of an unbiased CO survey of this longitude and latitude range in the velocity range from -60 to -10km/s. Over 500 molecular clouds (MCs) are picked out from the ^12^CO (J=1-0) emission, and 131 of these MCs are associated with ^13^CO emission. The distant MCs, which lie beyond the solar circle and are mostly concentrated in the Galactic plane, trace the large-scale molecular gas structure over 10 degrees of Galactic azimuth. We find that the distribution of the distant MCs can be well fitted by a Gaussian function with a full width at half maximum (FWHM) of 0.7{deg} with the Galactic latitude. We suggest that the CO emission of the segment is from the Outer Arm. The physical mid-plane traced by the Outer Arm seems to be slightly displaced from the IAU-defined plane on a large scale, which could be explained by the warped plane at large Galactocentric distances of >~10kpc and the apparent tilted mid-plane to the projected IAU-defined plane caused by the Sun's z-height above the disk for distances near and within the Solar circle. After removing the effect of the warp and tilted structure, the scale height of the MCs in the Outer Arm is about 0.6{deg} or 160pc at a heliocentric distance of 15kpc. If the inner plane of our Galaxy is flat, we can derive an upper limit of the Sun's offset of ~17.1pc above the physical mid-plane of the Milky Way. We also discuss the correlations between the physical parameters of the distant MCs, which is quite consistent with the result of other studies of this parameter.
- ID:
- ivo://CDS.VizieR/J/A+A/626/A20
- Title:
- MONOS. I. Spectral classifications
- Short Name:
- J/A+A/626/A20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Multiplicity in massive stars is a key element to understand the chemical and dynamical evolution of galaxies. Among massive stars, those of O type play a crucial role due to their high masses and short lifetimes. MONOS (Multiplicity Of Northern O-type Spectroscopic systems) is a project designed to collect information and study O-type spectroscopic binaries with {delta}>20{deg}. In this first paper we describe the sample and provide spectral classifications and additional information for objects with previous spectroscopic and/or eclipsing binary orbits. In future papers we will test the validity of previous solutions and calculate new spectroscopic orbits. The spectra in this paper have two sources: the Galactic O-Star Spectroscopic Survey (GOSSS), a project that is obtaining blue-violet R~2500 spectroscopy of thousands of massive stars, and LiLiMaRlin, a library of libraries of high-resolution spectroscopy of massive stars obtained from four different surveys (CAFE-BEANS, OWN, IACOB, and NoMaDS) and additional data from our own observing programs and public archives. We also use lucky images obtained with AstraLux. We present homogeneous spectral classifications for 92 O-type spectroscopic multiple systems and ten optical companions, many of them original.We discuss the visual multiplicity of each system with the support of AstraLux images and additional sources. For eleven O-type objects and for six B-type objects we present their first GOSSS spectral classifications. For two known eclipsing binaries we detect double absorption lines (SB2) or a single moving line (SB1) for the first time, to which we add a third system already reported by us recently. For two previous SB1 systems we detect their SB2 nature for the first time and give their first separate spectral classifications, something we also do for a third object just recently identified as a SB2. We also detect nine new astrometric companions and provide updated information on several others. We emphasize the results for two stars: for {sigma} Ori AaAbB we provide spectral classifications for the three components with a single observation for the first time thanks to a lucky spectroscopy observation obtained close to the Aa,Ab periastron and for {theta}^1^ Ori CaCb we add it to the class of Galactic Of?p stars, raising the number of its members to six. Our sample of O-type spectroscopic binaries contains more triple- or higher-order systems than double systems.
- ID:
- ivo://CDS.VizieR/J/A+A/562/A2
- Title:
- 100-month Swift catalogue of SFXTs
- Short Name:
- J/A+A/562/A2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Supergiant Fast X-ray Transients (SFXTs) are High Mass X-ray Binaries (HMXBs) that are defined by their hard X-ray flaring behaviour. During such flares they reach peak luminosities of 10^36^-10^37^erg/s for a few hours (in the hard X-ray): much shorter timescales than those characterizing Be/X-ray binaries. We investigate the characteristics of bright flares (detections in excess of 5{sigma}) for a sample of SFXTs and their relation to the orbital phase. We have retrieved all Swift/BAT Transient Monitor light curves, and collected all detections in excess of 5{sigma} from both daily- and orbital-averaged light curves in the time range 2005 February 12 to 2013 May 31 (MJD 53413-56443). We also considered all on-board detections as recorded in the same time span and selected those within 4 arcmin of each source in our sample and in excess of 5{sigma}. We present a catalogue of over a thousand BAT flares from 11 SFXTs, down to 15-150keV fluxes of ~6x10^-10^erg/cm^2^/s (daily timescale) and ~1.5x10^-9^erg/cm^2^/s (orbital timescale, averaging ~800s) and spanning 100 months. The great majority of these flares are unpublished. This population is characterized by short (a few hundred seconds) and relatively bright (in excess of 100mCrab, 15-50keV) events. In the hard X-ray, these flares last in general much less than a day. Clustering of hard X-ray flares can be used to indirectly measure the length of an outburst, even when the low-level emission is not detected. We construct the distributions of flares, of their significance (in terms of sigma) and their flux as a function of orbital phase, to infer the properties of these binary systems. In particular, we observe a trend of clustering of flares at some phases as P_orb increases, as consistent with a progression from tight, circular or mildly eccentric orbits at short periods, to wider and more eccentric orbits at longer orbital periods. Finally, we estimate the expected number of flares for a given source for our limiting flux and provide the recipe for calculating them for the limiting flux of future hard X-ray observatories.
