- ID:
- ivo://CDS.VizieR/J/ApJS/191/212
- Title:
- MIPS sources near the South Ecliptic Pole
- Short Name:
- J/ApJS/191/212
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have imaged an 11.5deg^2^ region of sky toward the South Ecliptic Pole (SEP; J0443-5340) at 24 and 70um with MIPS, the Multiband Imaging Photometer for Spitzer. This region is coincident with a field mapped at longer wavelengths by AKARI and BLAST. We discuss our data reduction and source extraction procedures. The median 1{sigma} depths of the maps are 47uJy/beam at 24um and 4.3mJy/beam at 70um. At 24um, we identify 93098 point sources with signal-to-noise ratio (S/N)>=5 and an additional 63 resolved galaxies; at 70um we identify 891 point sources with S/N>=6. From simulations, we determine a false detection rate of 1.8% (1.1%) for the 24um (70um) catalog. The 24 and 70um point-source catalogs are 80% complete at 230uJy and 11mJy, respectively.
Number of results to display per page
Search Results
1782. MIPS 24um calibrators
- ID:
- ivo://CDS.VizieR/J/PASP/119/994
- Title:
- MIPS 24um calibrators
- Short Name:
- J/PASP/119/994
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the stellar calibrator sample and the conversion from instrumental to physical units for the 24{mu}m channel of the Multiband Imaging Photometer for Spitzer (MIPS). The primary calibrators are A stars, and the calibration factor based on those stars is 4.54x10^-2^MJy/sr/(DN/s), with a nominal uncertainty of 2%. We discuss the data reduction procedures required to attain this accuracy; without these procedures, the calibration factor obtained using the automated pipeline at the Spitzer Science Center is 1.6%+/-0.6% lower. We extend this work to predict 24{mu}m flux densities for a sample of 238 stars that covers a larger range of flux densities and spectral types. We present a total of 348 measurements of 141 stars at 24{mu}m. This sample covers a factor of ~460 in 24{mu}m flux density, from 8.6mJy up to 4.0Jy. We show that the calibration is linear over that range with respect to target flux and background level. The calibration is based on observations made using 3s exposures; a preliminary analysis shows that the calibration factor may be 1% and 2% lower for 10 and 30s exposures, respectively. We also demonstrate that the calibration is very stable: over the course of the mission, repeated measurements of our routine calibrator, HD 159330, show a rms scatter of only 0.4%. Finally, we show that the point-spread function (PSF) is well measured and allows us to calibrate extended sources accurately; Infrared Astronomy Satellite (IRAS) and MIPS measurements of a sample of nearby galaxies are identical within the uncertainties.
1783. MIPS 24um nebulae
- ID:
- ivo://CDS.VizieR/J/MNRAS/405/1047
- Title:
- MIPS 24um nebulae
- Short Name:
- J/MNRAS/405/1047
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Massive evolved stars lose a large fraction of their mass via copious stellar wind or instant outbursts. During certain evolutionary phases, they can be identified by the presence of their circumstellar nebulae. In this paper, we present the results of a search for compact nebulae (reminiscent of circumstellar nebulae around evolved massive stars) using archival 24um data obtained with the Multiband Imaging Photometer for Spitzer. We have discovered 115 nebulae, most of which bear a striking resemblance to the circumstellar nebulae associated with luminous blue variables (LBVs) and late WN-type (WNL) Wolf-Rayet (WR) stars in the Milky Way and the Large Magellanic Cloud (LMC).
- ID:
- ivo://CDS.VizieR/J/ApJ/723/1110
- Title:
- MIPS 24um observations of the HDFS
- Short Name:
- J/ApJ/723/1110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present MIPS 24um observations of the Hubble Deep Field South taken with the Spitzer Space Telescope. The resulting image is 254arcmin^2^ in size and has a sensitivity ranging between ~12 and ~30uJy rms, with a median sensitivity of ~20uJy rms. A total of 495 sources have been catalogued with a signal-to-noise ratio greater than 5{sigma}. The source catalog is presented as well as source counts which have been corrected for completeness and flux boosting. The IR sources are then combined with MUSYC optical/NIR and ATHDFS radio observations to obtain redshifts and radio flux densities of the sample. We use the IR/radio flux density ratio (q_24_) to explore the IR-radio correlation for this IR sample and find q_24_=0.71+/-0.31 for sources detected in both IR and radio. The results are extended by stacking IR sources not detected in the radio observations and we derive an average q_24_ for redshift bins between 0<z<2.5. We find that the high-redshift (z>1) sources have an average q_24_ ratio which is better fit by local LIRG SEDs rather than local ULIRG SEDs, indicating that high-redshift ULIRGs differ in their IR/radio properties. So, ULIRGs at high-redshift have SEDs different from those found locally. Infrared-faint radio sources are examined, and while nine radio sources do not have an MIPS detection and are therefore radio-loud active galactic nuclei (AGNs), only one radio source has an extreme IRAC 3.6um to radio flux density ratio indicating it is a radio-loud AGN at z>1.
- ID:
- ivo://CDS.VizieR/J/ApJS/247/44
- Title:
- Mira-like variables from the KELT survey
- Short Name:
- J/ApJS/247/44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of 4132 Mira-like variables (red variables with long periods and high amplitudes) in the Kilodegree Extremely Little Telescope (KELT) survey. Of these, 376 are new Mira-like detections. We used Two Micron All Sky Survey (2MASS) colors to identify candidate asymptotic giant branch stars. We searched for photometric variability among the candidate asymptotic giant branch stars and identified stars that show periodic variability. We selected variables with high amplitudes and strong periodic behavior using a Random Forest classifier. Of the sample of 4132 Mira-like variables, we estimate that 70% are Miras and 30% are semiregular (SR) variables. We also adopt the method of using (W_RP_-W_Ks_) versus (J-Ks) colors in distinguishing between O-rich and C-rich Miras and find it to be an improvement over 2MASS colors.
- ID:
- ivo://CDS.VizieR/J/ApJS/232/16
- Title:
- Mira stars discovered in LAMOST DR4
- Short Name:
- J/ApJS/232/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on an extensive spectral study of a photometrically confirmed sample of Mira variables, we find a relationship between the relative Balmer emission-line strengths and spectral temperatures of O-rich Mira stars. The F_H{delta}_/F_H{gamma}_ flux ratio increases from less than unity to five as stars cool down from M0 to M10, which is likely driven by increasing TiO absorption above the deepest shock-emitting regions. We also discuss the relationship between the equivalent widths of the Balmer emission lines and the photometric luminosity phase of our Mira sample stars. Using our 291 Mira spectra as templates for reference, 191 Mira candidates are newly identified from the LAMOST DR4 catalog. We summarize the criteria adopted to select Mira candidates based on emission-line indices and molecular absorption bands. This enlarged spectral sample of Mira variables has the potential to contribute significantly to our knowledge of the optical properties of Mira stars and will facilitate further studies of these late-type, long-period variables.
- ID:
- ivo://CDS.VizieR/J/A+A/599/A29
- Title:
- MIR brightness contrast of Saturn's rings
- Short Name:
- J/A+A/599/A29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To investigate the mid-infrared (MIR) characteristics of Saturn's rings. We collected and analyzed MIR high spatial resolution images of Saturn's rings obtained in January 2008 and April 2005 with COMICS mounted on Subaru Telescope, and investigated the spatial variation in the surface brightness of the rings in multiple bands in the MIR. We also composed the spectral energy distributions (SEDs) of the C, B, and A rings and the Cassini Division, and estimated the temperatures of the rings from the SEDs assuming the optical depths. We find that the C ring and the Cassini Division were warmer than the B and A rings in 2008, which could be accounted for by their lower albedos, lower optical depths, and smaller self-shadowing effect. We also find that the C ring and the Cassini Division were considerably brighter than the B and A rings in the MIR in 2008 and the radial contrast of the ring brightness is the inverse of that in 2005, which is interpreted as a result of a seasonal effect with changing elevations of the sun and observer above the ring plane.
- ID:
- ivo://CDS.VizieR/J/ApJ/705/1364
- Title:
- MIR catalog of point sources in M33
- Short Name:
- J/ApJ/705/1364
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The progenitors of SN 2008S and the 2008 luminous transient in NGC 300 were deeply dust-enshrouded massive stars, with extremely red mid-infrared (MIR) colors and relatively low bolometric luminosities (~5x10^4^L_{sun}_). Because of the implied frequency of events similar to SN 2008S and NGC 300 and the interesting character of their progenitors, we searched for analogous sources in archival Spitzer imaging of nearby galaxies. Our goal was to identify the underlying subpopulation of massive stars from which these progenitors emerge, to characterize their properties and frequency, and to catalog them for future study. The Triangulum galaxy M33 is a perfect test case. It has an absolute B-band magnitude of M_B_~-19.2, a distance of ~0.96Mpc, and it has extensive optical, H{alpha}, MIR and FIR imaging.
- ID:
- ivo://CDS.VizieR/J/ApJS/252/32
- Title:
- MIR outbursts in nearby SDSS gal. (MIRONG). I.
- Short Name:
- J/ApJS/252/32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Optical time-domain astronomy has grown rapidly in the past decade, but the dynamic infrared sky is rarely explored. Aiming to construct a sample of mid-infrared outbursts in nearby galaxies (MIRONG), we have conducted a systematical search of low-redshift (z<0.35) Sloan Digital Sky Survey spectroscopic galaxies that have experienced recent mid-infrared (MIR) flares using their Wide-field Infrared Survey Explorer (WISE) light curves. A total of 137 galaxies have been selected by requiring a brightening amplitude of 0.5mag in at least one WISE band with respect to their quiescent phases. Only a small fraction (10.9%) has corresponding optical flares. Except for the four supernovae (SNe) in our sample, the MIR luminosities of the remaining sources (L_4.6{mu}m_>10^42^erg/s) are markedly brighter than known SNe, and their physical locations are very close to the galactic center (median <0.1"). Only four galaxies are radio-loud, indicating that synchrotron radiation from relativistic jets could contribute to MIR variability. We propose that these MIR outbursts are dominated by the dust echoes of transient accretion onto supermassive black holes, such as tidal disruption events (TDEs) and turn-on (changing-look) active galactic nuclei. Moreover, the inferred peak MIR luminosity function is generally consistent with the X-ray and optical TDEs at the high end, albeit with large uncertainties. Our results suggest that a large population of transients has been overlooked by optical surveys, probably due to dust obscuration or intrinsically optical weakness. Thus, a search in the infrared band is crucial for us to obtain a panoramic picture of nuclear outburst. The multiwavelength follow-up observations of the MIRONG sample are in progress and will be presented in a series of subsequent papers.
- ID:
- ivo://CDS.VizieR/J/ApJ/800/80
- Title:
- MIR properties of galaxies in A2199 at z~0.03
- Short Name:
- J/ApJ/800/80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the mid-infrared (MIR) properties of the galaxies in the A2199 supercluster at z=0.03 to understand the star formation activity of galaxy groups and clusters in the supercluster environment. Using the Wide-field Infrared Survey Explorer (WISE) data, we find no dependence of mass-normalized integrated star formation rates of galaxy groups/clusters on their virial masses. We classify the supercluster galaxies into three classes in the MIR color-luminosity diagram: MIR blue cloud (massive, quiescent, and mostly early-type), MIR star-forming sequence (mostly late-type), and MIR green valley galaxies. These MIR green valley galaxies are distinguishable from the optical green valley galaxies in the sense that they belong to the optical red sequence. We find that the fraction of each MIR class does not depend on the virial mass of each group/cluster. We compare the cumulative distributions of surface galaxy number density and cluster/group-centric distance for the three MIR classes. MIR green valley galaxies show the distribution between MIR blue cloud and MIR star-forming (SF) sequence galaxies. However, if we fix galaxy morphology, early- and late-type MIR green valley galaxies show different distributions. Our results suggest a possible evolutionary scenario of these galaxies: (1) late-type MIR SF sequence galaxies --> (2) late-type MIR green valley galaxies --> (3) early-type MIR green valley galaxies --> (4) early-type MIR blue cloud galaxies. In this sequence, the star formation of galaxies is quenched before the galaxies enter the MIR green valley, and then morphological transformation occurs in the MIR green valley.
