- ID:
- ivo://CDS.VizieR/J/AJ/152/142
- Title:
- Spitzer and WISE light curves of Neptune
- Short Name:
- J/AJ/152/142
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used the Spitzer Space Telescope in 2016 February to obtain high cadence, high signal-to-noise, 17hr duration light curves of Neptune at 3.6 and 4.5{mu}m. The light curve duration was chosen to correspond to the rotation period of Neptune. Both light curves are slowly varying with time, with full amplitudes of 1.1mag at 3.6{mu}m and 0.6mag at 4.5{mu}m. We have also extracted sparsely sampled 18hr light curves of Neptune at W1 (3.4{mu}m) and W2 (4.6{mu}m) from the Wide-feld Infrared Survey Explorer (WISE)/NEOWISE archive at six epochs in 2010-2015. These light curves all show similar shapes and amplitudes compared to the Spitzer light curves but with considerable variation from epoch to epoch. These amplitudes are much larger than those observed with Kepler/K2 in the visible (amplitude ~0.02mag) or at 845nm with the Hubble Space Telescope (HST) in 2015 and at 763nm in 2016 (amplitude ~0.2mag). We interpret the Spitzer and WISE light curves as arising entirely from reflected solar photons, from higher levels in Neptune's atmosphere than for K2. Methane gas is the dominant opacity source in Neptune's atmosphere, and methane absorption bands are present in the HST 763 and 845nm, WISE W1, and Spitzer 3.6{mu}m filters.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/218/33
- Title:
- Spitzer-CANDELS catalog within 5 deep fields
- Short Name:
- J/ApJS/218/33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Spitzer-Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (S-CANDELS; PI G.Fazio) is a Cycle 8 Exploration Program designed to detect galaxies at very high redshifts (z>5). To mitigate the effects of cosmic variance and also to take advantage of deep coextensive coverage in multiple bands by the Hubble Space Telescope (HST) Multi-cycle Treasury Program CANDELS, S-CANDELS was carried out within five widely separated extragalactic fields: the UKIDSS Ultra-deep Survey, the Extended Chandra Deep Field South, COSMOS, the HST Deep Field North, and the Extended Groth Strip. S-CANDELS builds upon the existing coverage of these fields from the Spitzer Extended Deep Survey (SEDS), a Cycle 6 Exploration Program, by increasing the integration time from SEDS' 12hr to a total of 50hr but within a smaller area, 0.16deg^2^. The additional depth significantly increases the survey completeness at faint magnitudes. This paper describes the S-CANDELS survey design, processing, and publicly available data products. We present Infrared Array Camera (IRAC) dual-band 3.6+4.5{mu}m catalogs reaching to a depth of 26.5 AB mag. Deep IRAC counts for the roughly 135000 galaxies detected by S-CANDELS are consistent with models based on known galaxy populations. The increase in depth beyond earlier Spitzer/IRAC surveys does not reveal a significant additional contribution from discrete sources to the diffuse Cosmic Infrared Background (CIB). Thus it remains true that only roughly half of the estimated CIB flux from COBE/DIRBE is resolved.
- ID:
- ivo://CDS.VizieR/J/ApJS/244/30
- Title:
- Spitzer catalog of Herschel star-forming galaxies
- Short Name:
- J/ApJS/244/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The largest Herschel extragalactic surveys, H-ATLAS and HerMES, have selected a sample of "ultrared" dusty star-forming galaxies (DSFGs) with rising SPIRE flux densities (S_500_>S_350_>S_250_; the so-called "500{mu}m risers") as an efficient way for identifying DSFGs at higher redshift (z>4). In this paper, we present a large Spitzer follow-up program of 300 Herschel ultrared DSFGs. We have obtained high-resolution Atacama Large Millimeter/submillimeter Array, Northern Extended Millimeter Array, and SMA data for 63 of them, which allow us to securely identify the Spitzer/IRAC counterparts and classify them as gravitationally lensed or unlensed. Within the 63 ultrared sources with high-resolution data, ~65% appear to be unlensed and ~27% are resolved into multiple components. We focus on analyzing the unlensed sample by directly performing multiwavelength spectral energy distribution modeling to derive their physical properties and compare with the more numerous z~2 DSFG population. The ultrared sample has a median redshift of 3.3, stellar mass of 3.7x10^11^M_{sun}_, star formation rate (SFR) of 730M_{sun}_/yr, total dust luminosity of 9.0x10^12^L_{sun}_, dust mass of 2.8x10^9^M_{sun}_, and V-band extinction of 4.0, which are all higher than those of the ALESS DSFGs. Based on the space density, SFR density, and stellar mass density estimates, we conclude that our ultrared sample cannot account for the majority of the star-forming progenitors of the massive, quiescent galaxies found in infrared surveys. Our sample contains the rarer, intrinsically most dusty, luminous, and massive galaxies in the early universe that will help us understand the physical drivers of extreme star formation.
- ID:
- ivo://CDS.VizieR/J/ApJS/177/551
- Title:
- Spitzer c2d survey of Lupus dark clouds
- Short Name:
- J/ApJS/177/551
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present c2d Spitzer IRAC observations of the Lupus I, III, and IV dark clouds and discuss them in combination with optical, near-infrared, and c2d MIPS data. With the Spitzer data, the new sample contains 159 stars, 4 times larger than the previous one. It is dominated by low- and very low mass stars, and it is complete down to M~0.1M_{sun}_. We find 30%-40% binaries with separations between 100 and 2000AU with no apparent effect on the disk properties of the members. A large majority of the objects are Class II or III objects, with only 20(12%) Class I or flat-spectrum sources. The disk sample is complete down to "debris"-like systems in stars as small as M~0.2M_{sun}_ and includes substellar objects with larger IR excesses. The disk fraction in Lupus is 70%-80%, consistent with an age of 1-2Myr. However, the young population contains 20% optically thick accretion disks and 40% relatively less flared disks. A growing variety of inner disk structures is found for larger inner disk clearings for equal disk masses.
- ID:
- ivo://CDS.VizieR/J/ApJ/669/493
- Title:
- Spitzer/Chandra YSOs in Serpens cloud core
- Short Name:
- J/ApJ/669/493
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Spitzer and Chandra observations of the nearby (~260pc) embedded stellar cluster in the Serpens cloud core. We observed, using Spitzer's IRAC and MIPS instruments, in six wavelength bands from 3 to 70um, to detect thermal emission from circumstellar disks and protostellar envelopes and to classify stars using color-color diagrams and SEDs. These data are combined with Chandra observations to examine the effects of circumstellar disks on stellar X-ray properties. Young diskless stars were also identified from their increased X-ray emission. We have identified 138 YSOs in Serpens: 22 Class 0/I, 16 flat-spectrum, 62 Class II, 17 transition disk, and 21 Class III stars; 60 of these exhibit X-ray emission.
- ID:
- ivo://CDS.VizieR/J/ApJ/686/966
- Title:
- Spitzer-FLS catalog of clusters of galaxies
- Short Name:
- J/ApJ/686/966
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 99 candidate clusters and groups of galaxies in the redshift range 0.1<z_phot_<1.3 discovered in the Spitzer First-Look Survey (FLS). The clusters are selected by their Rc-3.6um galaxy color-magnitude relation using the cluster red-sequence algorithm. Using this cluster sample, we compute the 3.6, 4.5, 5.8, and 8.0um, cluster luminosity functions (LFs).
- ID:
- ivo://CDS.VizieR/J/ApJ/899/123
- Title:
- Spitzer follow up of 95 brown dwarfs
- Short Name:
- J/ApJ/899/123
- Date:
- 14 Mar 2022 07:05:10
- Publisher:
- CDS
- Description:
- We present Spitzer follow-up imaging of 95 candidate extremely cold brown dwarfs discovered by the Backyard Worlds: Planet 9 citizen science project, which uses visually perceived motion in multiepoch Wide-field Infrared Survey Explorer (WISE) images to identify previously unrecognized substellar neighbors to the Sun. We measure Spitzer [3.6]-[4.5] color to phototype our brown dwarf candidates, with an emphasis on pinpointing the coldest and closest Y dwarfs within our sample. The combination of WISE and Spitzer astrometry provides quantitative confirmation of the transverse motion of 75 of our discoveries. Nine of our motion-confirmed objects have best-fit linear motions larger than 1"/yr; our fastest-moving discovery is WISEAJ155349.96+693355.2 ({mu}~2.15/yr), a possible T-type subdwarf. We also report a newly discovered wide-separation (~400au) T8 comoving companion to the white dwarf LSPMJ0055+5948 (the fourth such system to be found), plus a candidate late T companion to the white dwarf LSRJ0002+6357 at 5.5 projected separation (~8700au if associated). Among our motion-confirmed targets, five have Spitzer colors most consistent with spectral type Y. Four of these five have exceptionally red Spitzer colors suggesting types of Y1 or later, adding considerably to the small sample of known objects in this especially valuable low-temperature regime. Our Y dwarf candidates begin bridging the gap between the bulk of the Y dwarf population and the coldest known brown dwarf.
- ID:
- ivo://CDS.VizieR/J/ApJ/796/127
- Title:
- Spitzer h and {chi} Persei candidate members
- Short Name:
- J/ApJ/796/127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze very deep Infrared Array Camera and Multiband Imaging Photometer for Spitzer (MIPS) photometry of ~12500 members of the 14 Myr old Double Cluster, h and {chi} Persei, building upon our earlier, shallower Spitzer Cycle 1 studies. Numerous likely members show infrared (IR) excesses at 8 {mu}m and 24 {mu}m, indicative of circumstellar dust. The frequency of stars with 8 {mu}m excess is at least 2% for our entire sample, slightly lower (higher) for B/A stars (later type, lower mass stars). Optical spectroscopy also identifies gas in about 2% of systems, but with no clear trend between the presence of dust and gas. Spectral energy distribution modeling of 18 sources with detections at optical wavelengths through MIPS 24 {mu}m reveals a diverse set of disk evolutionary states, including a high fraction of transitional disks, though similar data for all disk-bearing members would provide constraints. Using Monte Carlo simulations, we combine our results with those for other young clusters to study the global evolution of dust/gas disks. For nominal cluster ages, the e-folding times ({tau}_0_) for the frequency of warm dust and gas are 2.75 Myr and 1.75 Myr, respectively. Assuming a revised set of ages for some clusters, these timescales increase to 5.75 and 3.75 Myr, respectively, implying a significantly longer typical protoplanetary disk lifetime than previously thought. In both cases, the transitional disk duration, averaged over multiple evolutionary pathways, is ~1 Myr. Finally, 24 {mu}m excess frequencies for 4-6 M_{sun}_ stars appear lower than for 1-2.5 M_{sun}_ stars in other 10-30 Myr old clusters.
- ID:
- ivo://CDS.VizieR/J/ApJ/750/125
- Title:
- Spitzer imaging of Cepheus OB3b cluster
- Short Name:
- J/ApJ/750/125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We map the full extent of a rich massive young cluster in the Cep OB3b association with the Infrared Array Camera and Multi-band Imaging Photometer System instruments aboard the Spitzer Space Telescope and the ACIS instrument aboard the Chandra X-Ray Observatory. At 700 pc, it is revealed to be the second nearest large (>1000 member), young (<5 Myr) cluster known. In contrast to the nearest large cluster, the Orion Nebula Cluster, Cep OB3b is only lightly obscured and is mostly located in a large cavity carved out of the surrounding molecular cloud. Our infrared and X-ray data sets, as well as visible photometry from the literature, are used to take a census of the young stars in Cep OB3b. We find that the young stars within the cluster are concentrated in two sub-clusters; an eastern sub-cluster, near the Cep B molecular clump, and a western sub-cluster, near the Cep F molecular clump. Using our census of young stars, we examine the fraction of young stars with infrared excesses indicative of circumstellar disks. We create a map of the disk fraction throughout the cluster and find that it is spatially variable. Due to these spatial variations, the two sub-clusters exhibit substantially different average disk fractions from each other: 32%+/-4% and 50%+/-6%. We discuss whether the discrepant disk fractions are due to the photodestruction of disks by the high mass members of the cluster or whether they result from differences in the ages of the sub-clusters. We conclude that the discrepant disk fractions are most likely due to differences in the ages.
- ID:
- ivo://CDS.VizieR/J/ApJ/755/9
- Title:
- Spitzer/IRAC light curves of GJ 436 system
- Short Name:
- J/ApJ/755/9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the detection of UCF-1.01, a strong exoplanet candidate with a radius 0.66+/-0.04 times that of Earth (R_{oplus}_). This sub-Earth sized planet transits the nearby M-dwarf star GJ 436 with a period of 1.365862+/-8x10^-6^ days. We also report evidence of a 0.65+/-0.06R_{Earth}_ exoplanet candidate (labeled UCF-1.02) orbiting the same star with an undetermined period. Using the Spitzer Space Telescope, we measure the dimming of light as the planets pass in front of their parent star to assess their sizes and orbital parameters. If confirmed today, UCF-1.01 and UCF-1.02 would be designated GJ 436c and GJ 436d, respectively, and would be part of the first multiple-transiting-planet system outside of the Kepler field. Assuming Earth-like densities of 5.515g/cm3, we predict both candidates to have similar masses (~0.28M_{oplus}_, 2.6 Mars-masses) and surface gravities of ~0.65g (where g is the gravity on Earth). UCF-1.01's equilibrium temperature (T_eq_, where emitted and absorbed radiation balance for an equivalent blackbody) is 860K, making the planet unlikely to harbor life as on Earth. Its weak gravitational field and close proximity to its host star imply that UCF-1.01 is unlikely to have retained its original atmosphere; however, a transient atmosphere is possible if recent impacts or tidal heating were to supply volatiles to the surface. We also present additional observations of GJ 436b during secondary eclipse. The 3.6{mu}m light curve shows indications of stellar activity, making a reliable secondary eclipse measurement impossible. A second non-detection at 4.5{mu}m supports our previous work in which we find a methane-deficient and carbon monoxide-rich dayside atmosphere.
