- ID:
- ivo://CDS.VizieR/J/ApJS/255/10
- Title:
- WISE MIR variability in gamma-ray Seyfert 1 gal.
- Short Name:
- J/ApJS/255/10
- Date:
- 11 Mar 2022
- Publisher:
- CDS
- Description:
- Fermi-LAT's detection of {gamma}-rays from narrow-line Seyfert 1 galaxies (NLS1s) has received increasing attention. Understanding these {gamma}-NLS1s is of interest because they have some properties similar to blazars, which are known to show rapid and large-amplitude variability. Based on the largest sample of {gamma}-NLS1s (25 sources), we carried out a systematic search for rapid mid-infrared (MIR, 3.4 and 4.6{mu}m) variability using the multiepoch data of the Wide-field Infrared Survey Explorer (WISE). We also compared a few variability properties between {gamma}-NLS1s and {gamma}-ray blazars. Our main results are as follows. (1) Thirteen {gamma}-NLS1s showed significant (>3{sigma}) rapid variability in at least one of the two MIR bands. The MIR emission of these sources is dominated by the synchrotron emission of relativistic electrons in the jet. (2) The {gamma}-NLS1s with flat radio spectra are more variable than those not detected in {gamma}-rays. (3) The {gamma}-NLS1s tend to show smaller amplitude of variability as well as lower duty cycle relative to {gamma}-ray blazars. (4) The {gamma}-NLS1s tend to show a trend of bluer-when-brighter on both intraday and long timescales, similar to {gamma}-ray blazars. (5) The {gamma}-NLS1s that are more variable on long timescales have larger amplitudes of variability and higher duty cycles on intraday timescales. (6) In the majority of cases, the {gamma}-NLS1s fall in the WISE Gamma-ray Blazar Strip (WGS). However, we noted migrations outside of the WGS due to significant variability.
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- ID:
- ivo://CDS.VizieR/J/A+A/564/A84
- Title:
- WISE model grids for O- and C-rich AGB
- Short Name:
- J/A+A/564/A84
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Since asymptotic giant branch (AGB) stars are bright and extended infrared objects, most Galactic AGB stars saturate the Wide-field Infrared Survey Explorer (WISE) detectors and therefore the WISE magnitudes that are restored by applying point-spread-function fitting need to be verified. Statistical properties of circumstellar envelopes around AGB stars are discussed on the basis of a WISE AGB catalog verified in this way. We cross-matched an AGB star sample with the WISE All-Sky Source Catalog and the Two Mircon All Sky Survey catalog. Infrared Space Observatory (ISO) spectra of a subsample of WISE AGB stars were also exploited. The dust radiation transfer code DUSTY was used to help predict the magnitudes in the W1 and W2 bands, the two WISE bands most affected by saturation, for calibration purpose, and to provide physical parameters of the AGB sample stars for analysis.
- ID:
- ivo://CDS.VizieR/J/A+A/603/A55
- Title:
- WISE/NEOWISE Mars-crossing asteroids
- Short Name:
- J/A+A/603/A55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Mars-crossing asteroids (MCs) are a dynamically unstable group between the main belt and the near-Earth populations. Characterising the physical properties of a large sample of MCs can help to understand the original sources of many near-Earth asteroids, some of which may produce meteorites on Earth. Our aim is to provide diameters and albedos of MCs with available WISE/NEOWISE data. We used the near-Earth asteroid thermal model to find the best-fitting values of equivalent diameter and, whenever possible, the infrared beaming parameter. With the diameter and tabulated asteroid absolute magnitudes we also computed the visible geometric albedos. We determined the diameters and beaming parameters of 404 objects observed during the fully cryogenic phase of the WISE mission, most of which have not been published elsewhere. We also obtained 1572 diameters from data from the 3-Band and posterior non-cryogenic phases using a default value of beaming parameter. The average beaming parameter is 1.2+/-0.2 for objects smaller than 10km, which constitute most of our sample. This is higher than the typical value of 1.0 found for the whole main belt and is possibly related to the fact that WISE is able to observe many more small objects at shorter heliocentric distances, i.e. at higher phase angles. We argue that this is a better default value for modelling Mars-crossing asteroids from the WISE/NEOWISE catalogue and discuss the effects of this choice on the diameter and albedo distributions. We find a double-peaked distribution for the visible geometric albedos, which is expected since this population is compositionally diverse and includes objects in the major spectral complexes. However, the distribution of beaming parameters is homogeneous for both low- and high-albedo objects.
- ID:
- ivo://CDS.VizieR/J/AJ/155/50
- Title:
- WISE photometry of Be stars in young open clusters
- Short Name:
- J/AJ/155/50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Through the modeling of near-infrared photometry of star-plus disk systems with the codes BEDISK/BERAY, we successfully describe the Wide-Field Infrared Survey Explorer (WISE) photometric characteristics of Be stars in five young open clusters, NGC 663, NGC 869, NGC 884, NGC 3766, and NGC 4755, broadly studied in the literature. WISE photometry allows previously known Be stars to be detected and to find new Be candidates which could be confirmed spectroscopically. The location of Be stars in the WISE color-magnitude diagram, separates them in two groups; active (Be stars hosting a developed circumstellar disk) and quiescent objects (Be stars in a diskless phase), and this way, we can explore how often stars are observed in these different stages. The variability observed in most active variable Be stars is compatible with a disk dissipation phase. We find that 50% of Be stars in the studied open clusters are in an active phase. We can interpret this as Be stars having a developed circumstellar disk one-half of the time. The location of Be stars with a developed disk in the color-magnitude diagram require mass loss rates in agreement with values recently reported in the literature. For these objects, we expect to have a tight relation between the equivalent width of the H{alpha} line and the mass of the disk, if the inclination is known. Also, near-infrared photometry of Be stars in stellar clusters has the potential of being useful to test whether there is a preferential viewing angle.
- ID:
- ivo://CDS.VizieR/J/ApJ/797/55
- Title:
- WISE photometry of dust-free stellar systems
- Short Name:
- J/ApJ/797/55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using data from the Wide-field Infrared Survey Explorer mission, we have measured near infra-red (NIR) photometry of a diverse sample of dust-free stellar systems (globular clusters, dwarf and giant early-type galaxies) which have metallicities that span the range -2.2<[Fe/H](dex)<0.3.
- ID:
- ivo://CDS.VizieR/II/307
- Title:
- WISE Preliminary Data Release
- Short Name:
- II/307
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Wide-field Infrared Survey Explorer (WISE; see Wright et al. 2010AJ....140.1868W) is a NASA Medium Class Explorer mission that conducted a digital imaging survey of the entire sky in the 3.4, 4.6, 12 and 22um mid-infrared bandpasses (hereafter W1, W2, W3 and W4). WISE will produce and release to the world astronomical and educational communities and general public a digital Image Atlas covering the sky in the four survey bands, and a reliable Source Catalog containing accurate photometry and astrometry for over 300 million objects. The WISE Catalog and Atlas will enable a broad variety of research efforts ranging from the search for the closest stars and brown dwarfs to the most luminous galaxies in the Universe. WISE science data products will serve as an important reference data set for planning observations and interpreting data obtained with future ground and space-borne observatories, such as JWST. WISE was launched on 2009-12-14 from Vandenberg SLC2W.
- ID:
- ivo://CDS.VizieR/J/ApJ/787/126
- Title:
- WISE reduced proper motions and spectral types
- Short Name:
- J/ApJ/787/126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of high proper motion objects that we have found in a recent study and in this work with multi-epoch astrometry from the Wide-field Infrared Survey Explorer (WISE). Using photometry and proper motions from the Two Micron All-Sky Survey and WISE, we have identified the members of this sample that are likely to be late-type, nearby, or metal-poor. We have performed optical and near-infrared spectroscopy on 41 objects, from which we measure spectral types that range from M4-T2.5. This sample includes 11 blue L dwarfs and 5 subdwarfs; the latter were also classified as such in the recent study by Kirkpatrick and coworkers. Based on their spectral types and photometry, several of our spectroscopic targets may have distances of <20 pc with the closest at ~12 pc. The tangential velocities implied by the spectrophotometric distances and proper motions indicate that four of the five subdwarfs are probably members of the Galactic halo while several other objects, including the early-T dwarf WISE J210529.08-623558.7, may belong to the thick disk.
- ID:
- ivo://CDS.VizieR/J/AJ/154/163
- Title:
- WISE-selected candidate SFRs beyond the Outer Arm
- Short Name:
- J/AJ/154/163
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The outer Galaxy beyond the Outer Arm provides a good opportunity to study star formation in an environment significantly different from that in the solar neighborhood. However, star-forming regions in the outer Galaxy have never been comprehensively studied or cataloged because of the difficulties in detecting them at such large distances. We studied 33 known young star-forming regions associated with 13 molecular clouds at R_G_>=13.5 kpc in the outer Galaxy with data from the Wide-field Infrared Survey Explorer (WISE) mid-infrared all-sky survey (Wright et al. 2010AJ....140.1868W; Jarrett et al. 2011ApJ...735..112J). From their color distribution, we developed a simple identification criterion of star-forming regions in the outer Galaxy with the WISE color. We applied the criterion to all the WISE sources in the molecular clouds in the outer Galaxy at R_G_>=13.5 kpc detected with the Five College Radio Astronomy Observatory (FCRAO) ^12^CO survey of the outer Galaxy (Heyer et al. 1998ApJS..115..241H), of which the survey region is 102.49{deg}=<l=<141.54{deg}, -3.03{deg}=<b=<5.41{deg}, and successfully identified 711 new candidate star-forming regions in 240 molecular clouds. The large number of samples enables us to perform the statistical study of star formation properties in the outer Galaxy for the first time. This study is crucial to investigate the fundamental star formation properties, including star formation rate, star formation efficiency, and initial mass function, in a primordial environment such as the early phase of the Galaxy formation.
- ID:
- ivo://CDS.VizieR/J/MNRAS/453/133
- Title:
- WISE view of RV Tauri stars
- Short Name:
- J/MNRAS/453/133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed study based on infrared (IR) photometry of all Galactic RV Tauri stars from the General Catalogue of Variable Stars (GCVS). RV Tauri stars are the brightest among the Population II Cepheids. They are thought to evolve away from the asymptotic giant branch (AGB) towards the white dwarf domain. IRAS detected several RV Tauri stars because of their large IR excesses and it was found that they occupy a specific region in the [12]-[25], [25]-[60] IRAS two-colour diagram. We used the all sky survey of Wide-field Infrared Survey Explorer to extend these studies and compare the IR properties of all RV Tauri stars in the GCVS with a selected sample of post-AGB objects with the goal to place the RV Tauri pulsators in the context of post-AGB evolution. Moreover, we correlated the IR properties of both the RV Tauri stars and the comparison sample with other observables like binarity and the presence of a photospheric chemical anomaly called depletion. We find that Galactic RV Tauri stars display a range of IR properties and we differentiate between disc sources, objects with no IR excess and objects for which the spectral energy distribution (SED) is uncertain. We obtain a clear correlation between disc sources and binarity. RV Tauri stars with a variable mean magnitude are exclusively found among the disc sources. We also find evidence for disc evolution among the binaries. Furthermore our studies show that the presence of a disc seems to be a necessary but not sufficient condition for the depletion process to become efficient.
- ID:
- ivo://CDS.VizieR/J/AJ/150/100
- Title:
- WISE YSO candidates near {sigma} and {lambda} Ori
- Short Name:
- J/AJ/150/100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a sensitive search down to the hydrogen burning limit for unextincted stars over ~200 square degrees around Lambda Orionis and 20 square degrees around Sigma Orionis using the methodology of Koenig & Leisawitz (2014ApJ...791..131K; K14). From WISE and 2MASS data we identify 544 and 418 candidate young stellar objects (YSOs) in the vicinity of {lambda} and {sigma} respectively. Based on our followup spectroscopy for some candidates and the existing literature for others, we found that ~80% of the K14-selected candidates are probable or likely members of the Orion star-forming region. The yield from the photometric selection criteria shows that WISE sources with K_S_-w3>1.5mag and K_S_ between 10 and 12mag are most likely to show spectroscopic signs of youth, while WISE sources with K_S_-w3>4mag and K_s_>12 were often active galactic nuclei when followed up spectroscopically. The population of candidate YSOs traces known areas of active star formation, with a few new "hot spots" of activity near Lynds 1588 and 1589 and a more dispersed population of YSOs in the northern half of the HII region bubble around {sigma} and {epsilon} Ori. A minimal spanning tree analysis of the two regions to identify stellar groupings finds that roughly two-thirds of the YSO candidates in each region belong to groups of 5 or more members. The population of stars selected by WISE outside the MST groupings also contains spectroscopically verified YSOs, with a local stellar density as low as 0.5 stars per square degree.
