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4231. Near-IR sources around IRAS 09002-4732
ID:
ivo://CDS.VizieR/J/A+A/434/987
Title:
Near-IR sources around IRAS 09002-4732
Short Name:
J/A+A/434/987
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present high-resolution near-infrared and mid-infrared imaging, mid-infrared spectroscopy and millimetre-wavelength continuum observations of the nearby massive star-forming complex IRAS 09002-4732. A rich cluster of young stars displaying near-infrared excess emission is detected. We identify the ionising source of the ultracompact H II region G268.42-0.85 and show that this star is the dominant heating and illuminating source of the region. Spectral type estimates based on different methods are consistent with a star of spectral type O9. The combination of the new observations with literature data allows us to set up the first structural model for the region.
4232. Near-IR Sources in the Cederblad 110 region.
ID:
ivo://CDS.VizieR/J/A+A/376/907
Title:
Near-IR Sources in the Cederblad 110 region.
Short Name:
J/A+A/376/907
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of deep (K_s_=18.9) sub-arcsec resolution (0.3") imaging observations of the Cederblad 110 region in the Chamaeleon I dark cloud. This region (roughly 5'x5') is characterized by the presence of six ISOCAM-detected young stellar objects (YSOs). Our images have recovered all these sources at near-infrared (near-IR) wavelengths. Ced 110 IRS4, the brightest object in the region, is associated with a remarkable near-IR bipolar nebulosity. Ced 110 IRS6 is resolved in a double system IRS6a and IRS6b with a separation of ~2" (~320AU at the distance of the Cha I cloud). We have combined 1.3 mm, far and mid-IR fluxes from the literature with our JHK data and obtained the spectral energy distributions (SEDs) for three (IRS4, IRS6a and ISO-ChaI86) of the six ISOCAM sources in the region. We modelled the SEDs of IRS6a and ISO-ChaI86 with a spherically symmetric dusty envelope, using the DUSTY code. These objects are clear Class I sources of the cloud. Finally, we report the detection of three new objects in this region (NIR 72, 84 and 89) with significant near-IR excess. If these sources are associated with the cloud, the derived luminosities and masses suggest that they are candidate young brown dwarfs of Chamaeleon I.
4233. Near-IR Spectrophotometry of GJ 3470b
ID:
ivo://CDS.VizieR/J/A+A/559/A33
Title:
Near-IR Spectrophotometry of GJ 3470b
Short Name:
J/A+A/559/A33
Date:
21 Oct 2021
Publisher:
CDS
Description:
This work presents time-series relative photometry of the planet-hosting star GJ 3470 during the transit of its 14 Earth-mass planet. Observations were obtained with the MOSFIRE near-infrared spectrograph from 2.09-2.36 micron, both in one single band and in six smaller bands. Reduction of the observations is described in the associated paper.
4234. Near-IR spectroscopy follow-up of 60 SDSS-DR7 QSOs
ID:
ivo://CDS.VizieR/J/ApJ/753/125
Title:
Near-IR spectroscopy follow-up of 60 SDSS-DR7 QSOs
Short Name:
J/ApJ/753/125
Date:
21 Oct 2021
Publisher:
CDS
Description:
Single-epoch virial black hole (BH) mass estimators utilizing broad emission lines have been routinely applied to high-redshift quasars to estimate their BH masses. Depending on the redshift, different line estimators (H{alpha}, H{beta}, MgII{lambda}2798, CIV{lambda}1549) are often used with optical/near-infrared spectroscopy. Here, we use a homogeneous sample of 60 intermediate-redshift (z~1.5-2.2) Sloan Digital Sky Survey quasars with optical and near-infrared spectra covering CIV through H{alpha} to investigate the consistency between different single-epoch virial BH mass estimators.
4235. Near-IR spectroscopy of low-mass binaries and brown dwarfs
ID:
ivo://CDS.VizieR/V/144
Title:
Near-IR spectroscopy of low-mass binaries and brown dwarfs
Short Name:
V/144
Date:
21 Oct 2021
Publisher:
CDS
Description:
The mass of a star at formation determines its subsequent evolution and demise. Low-mass stars are the most common products of star formation and their long main-sequence lifetimes cause them to accumulate over time. Star formation also produces many substellar-mass objects known as brown dwarfs, which emerge from their natal molecular clouds and continually cool as they age, pervading the Milky Way. Low-mass stars and brown dwarfs exhibit a wide range of physical characteristics and their abundance make them ideal subjects for testing formation and evolution models. I have examined a pair of pre-main sequence spectroscopic binaries and used radial velocity variations to determine orbital solutions and mass ratios. Additionally, I have employed synthetic spectra to estimate their effective temperatures and place them on theoretical Hertzsprung-Russell diagrams. From this analysis I discuss the formation and evolution of young binary systems and place bounds on absolute masses and radii. I have also studied the late-type T dwarfs revealed by the Wide-field Infrared Survey Explorer (WISE). This includes the exemplar T8 subdwarf Wolf 1130C, which has the lowest inferred metallicity in the literature and spectroscopic traits consistent with old age. Comparison to synthetic spectra implies that the dispersion in near-infrared colors of late-type T dwarfs is a result of age and/or thin sul de clouds. With the updated census of the L, T, and Y dwarfs we can now study specific brown dwarf subpopulations. Finally, I present a number of future studies that would develop our understanding of the physical qualities of T dwarf color outliers and disentangle the tracers of age and atmospheric properties. The thesis is available at: http://www.astro.ucla.edu/~gmace/thesis.html
4236. Near-IR surface photometry of Virgo galaxies
ID:
ivo://CDS.VizieR/J/A+AS/121/507
Title:
Near-IR surface photometry of Virgo galaxies
Short Name:
J/A+AS/121/507
Date:
21 Oct 2021
Publisher:
CDS
Description:
The basic parameters of galaxies observed in this work: table 3: total H and K' magnitudes derived using circular apertures; table 5: photometric parameters derived along elliptical apertures
4237. Near-IR survey of Class I protostars
ID:
ivo://CDS.VizieR/J/AJ/135/2496
Title:
Near-IR survey of Class I protostars
Short Name:
J/AJ/135/2496
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the observational results of a near-infrared survey of a large sample of Class I protostars designed to determine the Class I binary separation distribution from ~100AU to ~5000AU. We have selected targets from a new sample of 267 nearby candidate Class I objects. This sample is well understood, consists of mostly Class I young stellar objects (YSOs) within 1kpc, has targets selected from the whole sky, and is not biased by previous studies of star formation.
4238. NEOWISE/AllWISE high proper motion objects
ID:
ivo://CDS.VizieR/J/ApJ/817/112
Title:
NEOWISE/AllWISE high proper motion objects
Short Name:
J/ApJ/817/112
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Wide-field Infrared Survey Explorer (WISE) was reactivated in 2013 December (NEOWISE) to search for potentially hazardous near-Earth objects. We have conducted a survey using the first sky pass of NEOWISE data and the AllWISE catalog to identify nearby stars and brown dwarfs with large proper motions ({mu}_total_>~250mas/yr). A total of 20548 high proper motion objects were identified, 1006 of which are new discoveries. This survey has uncovered a significantly larger sample of fainter objects (W2>~13mag) than the previous WISE motion surveys of Luhman (2014, J/ApJ/781/4) and Kirkpatrick et al. (2014, J/ApJ/783/122). Many of these objects are predicted to be new L and T dwarfs based on near- and mid-infrared colors. Using estimated spectral types along with distance estimates, we have identified several objects that likely belong to the nearby solar neighborhood (d<25pc). We have followed up 19 of these new discoveries with near-infrared or optical spectroscopy, focusing on potentially nearby objects, objects with the latest predicted spectral types, and potential late-type subdwarfs. This subset includes six M dwarfs, five of which are likely subdwarfs, as well as eight L dwarfs and five T dwarfs, many of which have blue near-infrared colors. As an additional supplement, we provide 2MASS and AllWISE positions and photometry for every object found in our search, as well as 2MASS/AllWISE calculated proper motions.
4239. NEOWISE magnitudes for near-Earth objects
ID:
ivo://CDS.VizieR/J/ApJ/792/30
Title:
NEOWISE magnitudes for near-Earth objects
Short Name:
J/ApJ/792/30
Date:
21 Oct 2021
Publisher:
CDS
Description:
NASA's Wide-field Infrared Survey Explorer (WISE) spacecraft has been brought out of hibernation and has resumed surveying the sky at 3.4 and 4.6 {mu}m. The scientific objectives of the NEOWISE reactivation mission are to detect, track, and characterize near-Earth asteroids and comets. The search for minor planets resumed on 2013 December 23, and the first new near-Earth object (NEO) was discovered 6 days later. As an infrared survey, NEOWISE detects asteroids based on their thermal emission and is equally sensitive to high and low albedo objects; consequently, NEOWISE-discovered NEOs tend to be large and dark. Over the course of its three-year mission, NEOWISE will determine radiometrically derived diameters and albedos for ~2000 NEOs and tens of thousands of Main Belt asteroids. The 32 months of hibernation have had no significant effect on the mission's performance. Image quality, sensitivity, photometric and astrometric accuracy, completeness, and the rate of minor planet detections are all essentially unchanged from the prime mission's post-cryogenic phase.
4240. 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.