- ID:
- ivo://CDS.VizieR/J/ApJ/748/68
- Title:
- WISE IR colors of gamma-ray blazars
- Short Name:
- J/ApJ/748/68
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Blazars constitute the most enigmatic class of extragalactic {gamma}-ray sources, and their observational features have been ascribed to a relativistic jet closely aligned to the line of sight. They are generally divided in two main classes: the BL Lac objects (BL Lacs) and the flat-spectrum radio quasars (FSRQs). In the case of BL Lacs the double-bumped spectral energy distribution (SED) is generally described by the synchrotron self-Compton (SSC) emission, while for the FSRQs it is interpreted as due to external Compton (EC) emission. Recently, we showed that in the [3.4]-[4.6]-[12]{mu}m color-color diagram the blazar population covers a distinct region (i.e., the WISE blazar Strip (WBS)) clearly separated from the other extragalactic sources that are dominated by thermal emission. In this paper, we investigate the relation between the infrared and {gamma}-ray emission for a subset of confirmed blazars from the literature, associated with Fermi sources, for which WISE archival observations are available. This sample is a proper subset of the sample of sources used previously, and the availability of Fermi data is critical to constrain the models on the emission mechanisms for the blazars.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/837/15
- Title:
- WISE IR excesses among main sequence stars
- Short Name:
- J/ApJ/837/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This study presents a search for infrared (IR) excess in the 3.4, 4.6, 12, and 22{mu}m bands in a sample of 216 targets, composed of solar sibling, twin, and analog stars observed by the Wide-field Infrared Survey Explorer (WISE) mission. In general, an IR excess suggests the existence of warm dust around a star. We detected 12{mu}m and/or 22{mu}m excesses at the 3{sigma} level of confidence in five solar analog stars, corresponding to a frequency of 4.1% of the entire sample of solar analogs analyzed, and in one out of 29 solar sibling candidates, confirming previous studies. The estimation of the dust properties shows that the sources with IR excesses possess circumstellar material with temperatures that, within the uncertainties, are similar to that of the material found in the asteroid belt in our solar system. No photospheric flux excess was identified at the W1 (3.4{mu}m) and W2 (4.6{mu}m) WISE bands, indicating that, in the majority of stars of the present sample, no detectable dust is generated. Interestingly, among the 60 solar twin stars analyzed in this work, no WISE photospheric flux excess was detected. However, a null-detection excess does not necessarily indicate the absence of dust around a star because different causes, including dynamic processes and instrument limitations, can mask its presence.
- ID:
- ivo://CDS.VizieR/J/ApJS/212/10
- Title:
- WISE IR excesses for stars within 75pc
- Short Name:
- J/ApJS/212/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sensitive search for WISE W3 (12{mu}m) and W4 (22{mu}m) excesses from warm optically thin dust around Hipparcos main sequence stars within 75pc from the Sun. We use contemporaneously measured photometry from WISE, remove sources of contamination, and derive and apply corrections to saturated fluxes to attain optimal sensitivity to >10{mu}m excesses. We use data from the WISE All-Sky Survey Catalog rather than the AllWISE release because we find that its saturated photometry is better behaved, allowing us to detect small excesses even around saturated stars in WISE. Our new discoveries increase by 45% the number of stars with warm dusty excesses and expand the number of known debris disks (with excess at any wavelength) within 75pc by 29%. We identify 220 Hipparcos debris disk host stars, 108 of which are new detections at any wavelength. We present the first measurement of a 12{mu}m and/or 22{mu}m excess for 10 stars with previously known cold (50-100K) disks. We also find five new stars with small but significant W3 excesses, adding to the small population of known exozodi, and we detect evidence for a W2 excess around HIP 96562 (F2V), indicative of tenuous hot (780K) dust. As a result of our WISE study, the number of debris disks with known 10-30{mu}m excesses within 75pc (379) has now surpassed the number of disks with known >30{mu}m excesses (289, with 171 in common), even if the latter have been found to have a higher occurrence rate in unbiased samples.
- ID:
- ivo://CDS.VizieR/J/ApJ/835/280
- Title:
- WISE MIR properties of galaxies in compact groups
- Short Name:
- J/ApJ/835/280
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the mid-infrared (MIR) properties of galaxies in compact groups and their environmental dependence using the Wide-field Infrared Survey Explorer (WISE) data. We use a volume-limited sample of 670 compact groups and their 2175 member galaxies with M_r_<-19.77 and 0.01<z<0.0741, drawn from Sohn+ (2016, J/ApJS/225/23), which were identified using a friends-of-friends algorithm. Among the 2175 galaxies, 1541 galaxies are detected at WISE 12um with a signal-to-noise ratio greater than 3. Among the 1541 galaxies, 433 AGN-host galaxies are identified by using both optical and MIR classification schemes. Using the remaining 1108 non-AGN galaxies, we find that the MIR [3.4]-[12] colors of compact group early-type galaxies are on average bluer than those of cluster early-type galaxies. When compact groups have both early- and late-type member galaxies, the MIR colors of the late-type members in those compact groups are bluer than the MIR colors of cluster late-type galaxies. As compact groups are located in denser regions, they tend to have larger early-type galaxy fractions and bluer MIR color galaxies. These trends are also seen for neighboring galaxies around compact groups. However, compact group member galaxies always have larger early-type galaxy fractions and bluer MIR colors than their neighboring galaxies. Our findings suggest that the properties of compact group galaxies depend on both internal and external environments of compact groups, and that galaxy evolution is faster in compact groups than in the central regions of clusters.
- 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.
- 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.
