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1271. NEOWISE observations of 105 near-Earth objects
ID:
ivo://CDS.VizieR/J/ApJ/784/110
Title:
NEOWISE observations of 105 near-Earth objects
Short Name:
J/ApJ/784/110
Date:
21 Oct 2021
Publisher:
CDS
Description:
Only a very small fraction of the asteroid population at size scales comparable to the object that exploded over Chelyabinsk, Russia has been discovered to date, and physical properties are poorly characterized. We present previously unreported detections of 105 close approaching near-Earth objects (NEOs) by the Wide-field Infrared Survey Explorer (WISE) mission's NEOWISE project. These infrared observations constrain physical properties such as diameter and albedo for these objects, many of which are found to be smaller than 100m. Because these objects are intrinsically faint, they were detected by WISE during very close approaches to the Earth, often at large apparent on-sky velocities. We observe a trend of increasing albedo with decreasing size, but as this sample of NEOs was discovered by visible light surveys, it is likely that selection biases against finding small, dark NEOs influence this finding.
1272. NEOWISE observations of NEOs: preliminary results
ID:
ivo://CDS.VizieR/J/ApJ/743/156
Title:
NEOWISE observations of NEOs: preliminary results
Short Name:
J/ApJ/743/156
Date:
21 Oct 2021
Publisher:
CDS
Description:
With the NEOWISE portion of the Wide-field Infrared Survey Explorer (WISE) project, we have carried out a highly uniform survey of the near-Earth object (NEO) population at thermal infrared wavelengths ranging from 3 to 22um, allowing us to refine estimates of their numbers, sizes, and albedos. The NEOWISE survey detected NEOs the same way whether they were previously known or not, subject to the availability of ground-based follow-up observations, resulting in the discovery of more than 130 new NEOs. The survey's uniform sensitivity, observing cadence, and image quality have permitted extrapolation of the 428 near-Earth asteroids (NEAs) detected by NEOWISE during the fully cryogenic portion of the WISE mission to the larger population. We find that there are 981+/-19 NEAs larger than 1km and 20500+/-3000 NEAs larger than 100m. We show that the Spaceguard goal of detecting 90% of all 1km NEAs has been met, and that the cumulative size distribution is best represented by a broken power law with a slope of 1.32+/-0.14 below 1.5km. This power-law slope produces ~13200+/-1900 NEAs with D>140m. Although previous studies predict another break in the cumulative size distribution below D~50-100m, resulting in an increase in the number of NEOs in this size range and smaller, we did not detect enough objects to comment on this increase. The overall number for the NEA population between 100 and 1000m is lower than previous estimates. The numbers of near-Earth comets and potentially hazardous NEOs will be the subject of future work.
1273. NEOWISE reactivation mission: 2nd yr data
ID:
ivo://CDS.VizieR/J/AJ/152/63
Title:
NEOWISE reactivation mission: 2nd yr data
Short Name:
J/AJ/152/63
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Near-Earth Object Wide-Field Infrared Survey Explorer (NEOWISE) mission continues to detect, track, and characterize minor planets. We present diameters and albedos calculated from observations taken during the second year since the spacecraft was reactivated in late 2013. These include 207 near-Earth asteroids (NEAs) and 8885 other asteroids. Of the NEAs, 84% NEAs did not have previously measured diameters and albedos by the NEOWISE mission. Comparison of sizes and albedos calculated from NEOWISE measurements with those measured by occultations, spacecraft, and radar-derived shapes shows accuracy consistent with previous NEOWISE publications. Diameters and albedos fall within +/-~20% and +/-~40%, 1-sigma, respectively, of those measured by these alternate techniques. NEOWISE continues to preferentially discover near-Earth objects which are large (>100m), and have low albedos.
1274. NEOWISE Reactivation mission: 1st yr data
ID:
ivo://CDS.VizieR/J/ApJ/814/117
Title:
NEOWISE Reactivation mission: 1st yr data
Short Name:
J/ApJ/814/117
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present preliminary diameters and albedos for 7956 asteroids detected in the first year of the NEOWISE Reactivation mission. Of those, 201 are near-Earth asteroids and 7755 are Main Belt or Mars-crossing asteroids. 17% of these objects have not been previously characterized using the Near-Earth Object Wide-field Infrared Survey Explorer, or "NEOWISE" thermal measurements. Diameters are determined to an accuracy of ~20% or better. If good-quality H magnitudes are available, albedos can be determined to within ~40% or better.
1275. NEOWISE-R Known Solar System Object Possible Association List
ID:
ivo://irsa.ipac/WISE/Catalog/NEOWISE-R/SSOPAL
Title:
NEOWISE-R Known Solar System Object Possible Association List
Short Name:
NEOWISE-R SSOPAL
Date:
01 Oct 2018 20:27:16
Publisher:
NASA/IPAC Infrared Science Archive
Description:
The Near-Earth Object Wide-field Infrared Survey Explorer Reactivation Mission (NEOWISE; Mainzer et al. 2014, ApJ, 792, 30) is a NASA Planetary Science Division space-based survey to detect, track and characterize asteroids and comets, and to learn more about the population of near-Earth objects that could pose an impact hazard to the Earth. NEOWISE systematically images the sky at 3.4 and 4.6 μm, obtaining multiple independent observations on each location that enable detection of previously known and new solar system small bodies by virtue of the their motion. Because it is an infrared survey, NEOWISE detects asteroid thermal emission and is equally sensitive to high and low albedo objects. The Known Solar-System Object Possible Associations List is a compendium of asteroids, comets, planets or planetary satellites, with orbits known at the time of NEOWISE data processing, that were predicted to be within the field-of-view at the time of individual NEOWISE Single-exposures. Individual objects were observed multiple times, so may have multiple entries in the list. When the predicted position of a solar system object is in proximity to a detection in the NEOWISE Single-exposures, the NEOWISE detection position and brightness information are also provided.
1276. NEOWISE-R Single Exposure (L1b) Frame Metadata Table
ID:
ivo://irsa.ipac/WISE/Catalog/NEOWISE-R/Frame_Metadata
Title:
NEOWISE-R Single Exposure (L1b) Frame Metadata Table
Short Name:
NEOWISE-R Meta
Date:
01 Oct 2018 20:27:16
Publisher:
NASA/IPAC Infrared Science Archive
Description:
The Near-Earth Object Wide-field Infrared Survey Explorer Reactivation Mission (NEOWISE; Mainzer et al. 2014, ApJ, 792, 30) is a NASA Planetary Science Division space-based survey to detect, track and characterize asteroids and comets, and to learn more about the population of near-Earth objects that could pose an impact hazard to the Earth. NEOWISE systematically images the sky at 3.4 and 4.6 μm, obtaining multiple independent observations on each location that enable detection of previously known and new solar system small bodies by virtue of the their motion. Because it is an infrared survey, NEOWISE detects asteroid thermal emission and is equally sensitive to high and low albedo objects. The following table contains brief descriptions of all metadata information that is relevant to the processing of Single-exposure (level 1) images and the extraction of sources from the corresponding Single-exposure images. The table contains the unique scan ID and frame number for specific each single-exposure image and the reconstructed right ascension and declination of the image center. Much of the information in this table is processing-specific, and may not be of interest to general users (e.g. flags indicating whether frames have been processed or not, and the date and time for starting of the pipeline etc). The metadata table also contains some characterization and derived statistics of the Single-exposure image frames, basic parameters used for photometry and derived statistics for extracted sources and artifacts. For example, it contains the number of sources with profile-fit photometry Signal-to-Noise (SNR) greater than 3, and the total number of real sources affected by artifacts such as latent images and electronic ghosts.
1277. NEOWISE-R Single Exposure (L1b) Source Table
ID:
ivo://irsa.ipac/WISE/Catalog/NEOWISE-R/Source_Table
Title:
NEOWISE-R Single Exposure (L1b) Source Table
Short Name:
NEOWISE-R ST
Date:
01 Oct 2018 20:27:16
Publisher:
NASA/IPAC Infrared Science Archive
Description:
The Near-Earth Object Wide-field Infrared Survey Explorer Reactivation Mission (NEOWISE; Mainzer et al. 2014, ApJ, 792, 30) is a NASA Planetary Science Division space-based survey to detect, track and characterize asteroids and comets, and to learn more about the population of near-Earth objects that could pose an impact hazard to the Earth. NEOWISE systematically images the sky at 3.4 and 4.6 μm, obtaining multiple independent observations on each location that enable detection of previously known and new solar system small bodies by virtue of the their motion. Because it is an infrared survey, NEOWISE detects asteroid thermal emission and is equally sensitive to high and low albedo objects. The Single-exposure Source Database is a compendium of position and flux information for source detections made on the individual NEOWISE 7.7s W1 and W2 Single-exposure images. Because NEOWISE scanned the same region of the sky multiple times, the Single-exposure Database contains multiple, independent measurements of objects. Positions, magnitudes in the two NEOWISE bands, astrometric and photometric uncertainties, flags indicating measurement quality, the time of observations and associations with the AllWISE Source Catalog and 2MASS Point Source Catalog are presented for entries in the Database.
1278. NEOWISE: thermal model fits for NEOs and MBAs
ID:
ivo://CDS.VizieR/J/AJ/154/168
Title:
NEOWISE: thermal model fits for NEOs and MBAs
Short Name:
J/AJ/154/168
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Near-Earth ObjectWide-field Infrared Survey Explorer (NEOWISE) reactivation mission has completed its third year of surveying the sky in the thermal infrared for near-Earth asteroids and comets. NEOWISE collects simultaneous observations at 3.4 and 4.6 {mu}m of solar system objects passing through its field of regard. These data allow for the determination of total thermal emission from bodies in the inner solar system, and thus the sizes of these objects. In this paper, we present thermal model fits of asteroid diameters for 170 NEOs and 6110 Main Belt asteroids (MBAs) detected during the third year of the survey, as well as the associated optical geometric albedos. We compare our results with previous thermal model results from NEOWISE for overlapping sample sets, as well as diameters determined through other independent methods, and find that our diameter measurements for NEOs agree to within 26% (1{sigma}) of previously measured values. Diameters for the MBAs are within 17% (1{sigma}). This brings the total number of unique near-Earth objects characterized by the NEOWISE survey to 541, surpassing the number observed during the fully cryogenic mission in 2010.
1279. NEP deep survey at 11um
ID:
ivo://CDS.VizieR/J/PASJ/59/S529
Title:
NEP deep survey at 11um
Short Name:
J/PASJ/59/S529
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the properties of 11um selected sources detected in the early data of the North Ecliptic Pole Deep (NEP-Deep) Survey of AKARI. The data set covers 6 wavelength bands from 2.5 to 11um, with exposure times of 10-20 minutes. This field lies within the CFHT survey with four filter bands (g', r', i', z'), enabling us to establish nearly continuous spectral energy distributions (SEDs) for wavelengths ranging from 0.4 to 11um. The main sample studied here consists of 72 sources whose 11um AB magnitudes are equal to or brighter than 18.5 (144uJy), which is complete to more than 90%. The 11um band has an advantage of sampling star-forming galaxies with low-to-medium redshifts, since the prominent PAH feature shifts into this band. As expected, we find that the majority (71%) of 11um bright sources are star-forming galaxies at 0.2~<z~<0.7 with L_IR_~10^10^-10^12^~L_{sun}_ based on detailed modelling of the SEDs. We also find four AGNs lying at various redshifts in the main sample. In addition, we discuss a few sources that have non-typical SEDs of the main sample, including a brown-dwarf candidate, a steep power-law source, a flat-spectrum object, and an early-type galaxy at moderate redshift.
1280. NEP raster ROSAT X-ray/Optical catalog
ID:
ivo://CDS.VizieR/J/A+A/645/A95
Title:
NEP raster ROSAT X-ray/Optical catalog
Short Name:
J/A+A/645/A95
Date:
21 Oct 2021
Publisher:
CDS
Description:
The North-Ecliptic Pole is an important region for extragalactic surveys. Deep/wide contiguous surveys are being performed by several space observatories. We analyse all ROSAT pointed and survey observations within 40deg^2^ around the NEP, restricting the field-of-view to the inner 30' radius. We obtain an X-ray catalogue of 805 sources with 0.5-2keV fluxes >2.9*10^-15^erg/cm^2^/s, a factor of three deeper than the ROSAT All-Sky Survey in this field. The sensitivity and angular resolution of our data are comparable to the eROSITA All-Sky Survey expectations. The 50% position error radius of the sample of X-ray sources is ~10". We use HEROES optical and near-infrared imaging photometry from Subaru and CFHT telescopes together with literature catalogues and a new deep and wide Spitzer survey in the field to identify X-ray sources and calculate photometric redshifts for the candidate counterparts. In particular we utilize mid-IR colours to identify AGN X-ray counterparts. Despite relatively large error circles and faint counterparts, confusion and systematic errors, we obtain a rather reliable catalogue of 766 optical counterparts, redshifts and optical classifications. We find a new population of luminous absorbed X-ray AGN at large redshifts, not recognized in previous X-ray surveys, but identified in our work due to the unique combination of survey solid angle, X-ray sensitivity and multiwavelength photometry. We also use the WISE and Spitzer photometry to identify a sample of 185 AGN selected purely through mid-IR colours, most of which are not detected by ROSAT. Their redshifts and upper limits to X-ray luminosity and X-ray-to-optical flux ratios are even higher than for the new class of X-ray selected luminous type 2 AGN (AGN2); they are probably a natural extension of this sample. This unique dataset is important as a reference sample for future deep surveys in the NEP region, in particular for eROSITA and also for Euclid and SPHEREX. We predict that most of the absorbed distant AGN should be readily picked up by eROSITA, but they require sensitive mid-IR imaging to be recognized as optical counterparts.

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