- ID:
- ivo://CDS.VizieR/J/ApJ/777/97
- Title:
- SL2S galaxy-scale lens sample. III.
- Short Name:
- J/ApJ/777/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Hubble Space Telescope (HST) imaging data and Canada-France-Hawaii Telescope (CFHT) near-infrared ground-based images for the final sample of 56 candidate galaxy-scale lenses uncovered in the CFHT Legacy Survey as part of the Strong Lensing in the Legacy Survey (SL2S) project. The new images are used to perform lens modeling, measure surface photometry, and estimate stellar masses of the deflector early-type galaxies (ETGs). Lens modeling is performed on the HST images (or CFHT when HST is not available) by fitting the spatially extended light distribution of the lensed features assuming a singular isothermal ellipsoid mass profile and by reconstructing the intrinsic source light distribution on a pixelized grid. Based on the analysis of systematic uncertainties and comparison with inference based on different methods, we estimate that our Einstein radii are accurate to ~3%. HST imaging provides a much higher success rate in confirming gravitational lenses and measuring their Einstein radii than CFHT imaging does. Lens modeling with ground-based images, however, when successful, yields Einstein radius measurements that are competitive with space-based images. Information from the lens models is used together with spectroscopic information from companion Paper IV (2013ApJ...777...98S) to classify the systems, resulting in a final sample of 39 confirmed (grade A) lenses and 17 promising candidates (grade B,C).
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/215/15
- Title:
- SMaSH+: observations and companion detection
- Short Name:
- J/ApJS/215/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Multiplicity is one of the most fundamental observable properties of massive O-type stars and offers a promising way to discriminate between massive star formation theories. Nevertheless, companions at separations between 1 and 100 milliarcsec (mas) remain mostly unknown due to intrinsic observational limitations. At a typical distance of 2kpc, this corresponds to projected physical separations of 2-200AU. The Southern MAssive Stars at High angular resolution survey (SMaSH+) was designed to fill this gap by providing the first systematic interferometric survey of Galactic massive stars. We observed 117 O-type stars with VLTI/PIONIER and 162 O-type stars with NACO/Sparse Aperture Masking (SAM), probing the separation ranges 1-45 and 30-250mas and brightness contrasts of {Delta}H<4 and {Delta}H<5, respectively. Taking advantage of NACO's field of view, we further uniformly searched for visual companions in an 8" radius down to {Delta}H=8. This paper describes observations and data analysis, reports the discovery of almost 200 new companions in the separation range from 1mas to 8" and presents a catalog of detections, including the first resolved measurements of over a dozen known long-period spectroscopic binaries. Excluding known runaway stars for which no companions are detected, 96 objects in our main sample ({delta}<0{deg}; H<7.5) were observed both with PIONIER and NACO/SAM. The fraction of these stars with at least one resolved companion within 200mas is 0.53. Accounting for known but unresolved spectroscopic or eclipsing companions, the multiplicity fraction at separation {rho}<8" increases to f_m_=0.91+/-0.03. The nine non-thermal radio emitters observed by SMaSH+ are all resolved, including the newly discovered pairs HD 168112 and CPD-47{deg}2963.
- ID:
- ivo://CDS.VizieR/J/A+A/564/A31
- Title:
- SMC blob N26 multiband photometry
- Short Name:
- J/A+A/564/A31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-excitation compact HII regions of the Magellanic Clouds are sites of recent massive star formation in low metallicity environments. Detailed study of these regions and their environments using high-spatial resolution observations is necessary to better understand massive star formation, which is still an unsolved problem. We aim at a detailed study of the Small Magellanic Cloud compact HII region N26, which is only ~4" in diameter. This study is based on high spatial resolution imaging (~0.1"-0.3") in JHKs and L' bands, using the VLT equipped with the NAOS adaptive optics system. A larger region (~50pcx76pc) was also imaged at medium spatial resolution, using the ESO 2.2m telescope in optical wavelengths. We also used the JHKs archival data from the IRSF survey and the Spitzer Space Telescope SAGE-SMC survey.
- ID:
- ivo://CDS.VizieR/J/ApJ/771/111
- Title:
- SMC dusty OB stars. I. Optical spectroscopy
- Short Name:
- J/ApJ/771/111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of optical spectroscopic follow-up of 125 candidate main sequence OB stars in the Small Magellanic Cloud (SMC) that were originally identified in the S^3^MC infrared imaging survey as showing an excess of emission at 24{mu}m indicative of warm dust, such as that associated with a transitional or debris disks. We use these long-slit spectra to investigate the origin of the 24{mu}m emission and the nature of these stars. A possible explanation for the observed 24{mu}m excess, that these are emission line stars with dusty excretion disks, is disproven for the majority of our sources. We find that 88 of these objects are normal stars without line emission, with spectral types mostly ranging from late-O to early-B; luminosity classes from the literature for a sub-set of our sample indicate that most are main-sequence stars. We further identify 17 emission-line stars, 7 possible emission-line stars, and 5 other objects with forbidden-line emission in our sample. We discover a new O6 Iaf star; it exhibits strong HeII4686{AA} emission but relatively weak NIII4640{AA} emission which we attribute to the lower nitrogen abundance in the SMC. Two other objects are identified with planetary nebulae, one with a young stellar object, and two with X-ray binaries. To shed additional light on the nature of the observed 24{mu}m excess we use optical and infrared photometry to estimate the dust properties of the objects with normal O and B star spectra and compare these properties to those of a sample of hot spots in the Galactic interstellar medium (ISM).
- ID:
- ivo://CDS.VizieR/J/ApJ/655/212
- Title:
- S3MC IRAC and MIPS photometry
- Short Name:
- J/ApJ/655/212
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the initial results from the Spitzer Survey of the Small Magellanic Cloud (S^3^MC), which imaged the star-forming body of the SMC in all seven MIPS and IRAC wave bands. We find that the F8/F24 ratio (an estimate of PAH abundance) has large spatial variations and takes a wide range of values that are unrelated to metallicity but anticorrelated with 24um brightness and F24/F70 ratio. This suggests that photodestruction is primarily responsible for the low abundance of PAHs observed in star-forming low-metallicity galaxies. We use the S^3^MC images to compile a photometric catalog of 400000 mid- and far-infrared point sources in the SMC.
- ID:
- ivo://CDS.VizieR/J/ApJ/689/377
- Title:
- SNe Ia as NIR standard candles from PAIRITEL
- Short Name:
- J/ApJ/689/377
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained 1087 NIR (JHK_s_) measurements of 21 SNe Ia using PAIRITEL, nearly doubling the number of well-sampled NIR SN Ia light curves. These data strengthen the evidence that SNe Ia are excellent standard candles in the NIR, even without correction for optical light-curve shape. We construct fiducial NIR templates for normal SNe Ia from our sample, excluding only the three known peculiar SNe Ia: SN 2005bl, SN 2005hk, and SN 2005ke. The H-band absolute magnitudes in this sample of 18 SNe Ia have an intrinsic rms of only 0.15mag with no correction for light-curve shape. We found a relationship between the H-band extinction and optical color excess of A_H_=0.2E(B-V). This variation is as small as the scatter in distance modulus measurements currently used for cosmology based on optical light curves after corrections for light-curve shape. Combining the homogeneous PAIRITEL measurements with 23 SNe Ia from the literature, these 41 SNe Ia have standard H-band magnitudes with an rms scatter of 0.16mag. The good match of our sample with the literature sample suggests there are few systematic problems with the photometry.
- ID:
- ivo://CDS.VizieR/J/ApJS/233/6
- Title:
- SNe II light curves & spectra from the CfA
- Short Name:
- J/ApJS/233/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multiband photometry of 60 spectroscopically confirmed supernovae (SNe): 39 SNe II/IIP, 19 IIn, 1 IIb, and 1 that was originally classified as a IIn but later as a Ibn. Of these, 46 have only optical photometry, 6 have only near-infrared (NIR) photometry, and 8 have both optical and NIR. The median redshift of the sample is 0.016. We also present 195 optical spectra for 48 of the 60 SN. There are 26 optical and 2 NIR light curves of SNe II/IIP with redshifts z>0.01, some of which may give rise to useful distances for cosmological applications. All photometry was obtained between 2000 and 2011 at the Fred Lawrence Whipple Observatory (FLWO), via the 1.2m and 1.3m PAIRITEL telescopes for the optical and NIR, respectively. Each SN was observed in a subset of the u'UBVRIr'i'JHK_s_ bands. There are a total of 2932 optical and 816 NIR light curve points. Optical spectra were obtained using the FLWO 1.5m Tillinghast telescope with the FAST spectrograph and the MMT Telescope with the Blue Channel Spectrograph. Our photometry is in reasonable agreement with select samples from the literature: two-thirds of our star sequences have average V offsets within +/-0.02mag and roughly three-quarters of our light curves have average differences within +/-0.04mag. The data from this work and the literature will provide insight into SN II explosions, help with developing methods for photometric SN classification, and contribute to their use as cosmological distance indicators.
- ID:
- ivo://CDS.VizieR/J/A+A/611/A58
- Title:
- SN 2007on and SN 2011iv light curves
- Short Name:
- J/A+A/611/A58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of ultraviolet (UV) to near-infrared observations of the fast-declining Type Ia supernovae (SNe Ia) 2007on and 2011iv, hosted by the Fornax cluster member NGC 1404. The B-band light curves of SN 2007on and SN 2011iv are characterised by {Delta}m15(B) decline-rate values of 1.96mag and 1.77mag, respectively. Although they have similar decline rates, their peak B- and H-band magnitudes differ by ~0.60mag and ~0.35mag, respectively. After correcting for the luminosity vs. decline rate and the luminosity vs. colour relations, the peak B-band and H-band light curves provide distances that differ by ~14% and ~9%, respectively. These findings serve as a cautionary tale for the use of transitional SNe Ia located in early-type hosts in the quest to measure cosmological parameters. Interestingly, even though SN 2011iv is brighter and bluer at early times, by three weeks past maximum and extending over several months, its B-V colour is 0.12mag redder than that of SN 2007on. To reconcile this unusual behaviour, we turn to guidance from a suite of spherical one-dimensional Chandrasekhar-mass delayed-detonation explosion models. In this context, ^56^Ni production depends on both the so-called transition density and the central density of the progenitor white dwarf. To first order, the transition density drives the luminosity-width relation, while the central density is an important second-order parameter. Within this context, the differences in the B-V colour evolution along the Lira regime suggest that the progenitor of SN 2011iv had a higher central density than SN 2007on.
- ID:
- ivo://CDS.VizieR/J/ApJ/874/16
- Title:
- SOFIA Massive Star Formation Survey. II. 7 protostars
- Short Name:
- J/ApJ/874/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multiwavelength images observed with SOFIA-FORCAST from ~10 to 40{mu}m of seven high luminosity massive protostars, as part of the SOFIA Massive Star Formation Survey. Source morphologies at these wavelengths appear to be influenced by outflow cavities and extinction from dense gas surrounding the protostars. Using these images, we build spectral energy distributions (SEDs) of the protostars, also including archival data from Spitzer, Herschel, and other facilities. Radiative transfer (RT) models of Zhang & Tan (2018ApJ...853...18Z), based on Turbulent Core Accretion theory, are then fit to the SEDs to estimate key properties of the protostars. Considering the best five models fit to each source, the protostars have masses m*~12-64M_{sun}_ accreting at rates of dm/dt_*_~10^-4^-10^-3^M_{sun}_/yr inside cores of initial masses M_c_~100-500M_{sun}_ embedded in clumps with mass surface densities {Sigma}_cl_~0.1-3g/cm^2^ and span a luminosity range of 10^4^-10^6^L_{sun}_. Compared with the first eight protostars in Paper I (De Buizer+ 2017ApJ...843...33D), the sources analyzed here are more luminous and, thus, likely to be more massive protostars. They are often in a clustered environment or have a companion protostar relatively nearby. From the range of parameter space of the models, we do not see any evidence that {Sigma}cl needs to be high to form these massive stars. For most sources, the RT models provide reasonable fits to the SEDs, though the cold clump material often influences the long wavelength fitting. However, for sources in very clustered environments, the model SEDs may not be such a good description of the data, indicating potential limitations of the models for these regions.
- ID:
- ivo://CDS.VizieR/J/A+A/399/995
- Title:
- SOFI and ISOCAM observations of Cha II
- Short Name:
- J/A+A/399/995
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An infrared study including ISOCAM images at 6.75 and 14.3{mu}m of a large portion (28'x26') of the Chamaeleon II dark cloud and sub-arcsec resolution JHKs images of the central (4.9'x4.9') area is presented. Combining the ISOCAM observations with J and Ks photometry obtained with DENIS, we have found 12 young stars, of which 8 are previously identified sources.
