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2671. Spectrum of V4332 Sgr in 2005
ID:
ivo://CDS.VizieR/J/A+A/578/A75
Title:
Spectrum of V4332 Sgr in 2005
Short Name:
J/A+A/578/A75
Date:
21 Oct 2021
Publisher:
CDS
Description:
V4332 Sgr is a red transient (red nova) whose eruption was observed in 1994. The remnant of the eruption shows a unique optical spectrum: strong emission lines of atomes and molecules superimposed on a M-type stellar spectrum. The stellar-like remnant is presumably embedded in a disc-like dusty envelope orientated almost face-on. The observed optical spectrum is supposed to result from interactions of the central-star radiation with dust and gas in the disc and outflows initiated in 1994. We have reduced and measured a high-resolution (R~40000) spectrum of V4332 Sgr obtained with VLT/UVES in April/May 2005. The spectrum comes from the ESO archives and is the best quality spectrum of the object ever obtained. We have identified and measured over 200 emission features belonging to 11 elements and 6 molecules. The continuous, stellar-like component can be classified as ~M3. The radial velocity of the object, as derived from narrow atomic emission line, is -75km/s. The interstellar reddening was estimated as being 0.35<E(B-V)<0.75. From radial velocities of interstellar absorption features in the NaI D lines we have estimated a lower limit of ~5.5 kpc to the distance of V4332 Sgr. When compared to spectroscopic observations done in 2009, the spectrum of V4332 Sgr considerably evolved between 2005 and 2009. The object significantly faded in the optical (by ~2mag in the V band), which resulted from the main remnant cooled by 300-350K corresponding to its spectral type changed from M3 to M5-6. The object however increased in luminosity by ~50%, implying a significant expansion of its dimensions. Most of the emission features seen in 2005 significantly faded or even disappeared from the spectrum of V4332 Sgr in 2009.
2672. SpeX NIR survey of 886 nearby M dwarfs
ID:
ivo://CDS.VizieR/J/ApJS/220/16
Title:
SpeX NIR survey of 886 nearby M dwarfs
Short Name:
J/ApJS/220/16
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of near-infrared (NIR) spectra and associated measurements for 886 nearby M dwarfs. The spectra were obtained with the NASA-Infrared Telescope Facility SpeX Spectrograph during a two-year observing campaign; they have high signal-to-noise ratios (S/N>100-150), span 0.8-2.4{mu}m, and have R~2000. Our catalog of measured values contains useful T_eff_ and composition-sensitive features, empirical stellar parameter measurements, and kinematic, photometric, and astrometric properties compiled from the literature. We focus on measurements of M dwarf abundances ([Fe/H] and [M/H]), capitalizing on the precision of recently published empirical NIR spectroscopic calibrations. We explore systematic differences between different abundance calibrations, and from other similar M dwarf catalogs. We confirm that the M dwarf abundances we measure show the expected inverse dependence with kinematic-, activity-, and color-based age indicators. Finally, we provide updated [Fe/H] and [M/H] for 16 M dwarf planet hosts. This catalog represents the largest published compilation of NIR spectra and associated parameters for M dwarfs. It provides a rich and uniform resource for nearby M dwarfs, and will be especially valuable for measuring Habitable Zone locations and comparative abundances of the M dwarf planet hosts that will be uncovered by upcoming exoplanet surveys.
2673. SpeX spectroscopy of low mass binaries. I.
ID:
ivo://CDS.VizieR/J/ApJ/710/1142
Title:
SpeX spectroscopy of low mass binaries. I.
Short Name:
J/ApJ/710/1142
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the identification of 17 candidate brown dwarf binaries whose components straddle the L dwarf/T dwarf transition. These sources were culled from a large near-infrared spectral sample of L and T dwarfs observed with the Infrared Telescope Facility SpeX spectrograph. Candidates were selected on the basis of spectral ratios which segregate known (resolved) L dwarf/T dwarf pairs from presumably single sources. Composite templates, constructed by combining 13581 pairs of absolute flux-calibrated spectra, are shown to provide statistically superior fits to the spectra of our 17 candidates as compared to single templates. Ten of these candidates appear to have secondary components that are significantly brighter than their primaries over the 1.0-1.3um band, indicative of rapid condensate depletion at the L dwarf/T dwarf transition. Our results support prior indications of enhanced multiplicity amongst early-type T dwarfs; 53+/-7% of the T0-T4 dwarfs in our spectral sample are found to be either resolved or unresolved (candidate) pairs, although this is consistent with an intrinsic (volume complete) brown dwarf binary fraction of only 15%. If verified, this sample of spectral binaries more than doubles the number of known L dwarf/T dwarf transition pairs, enabling a broader exploration of this poorly understood phase of brown dwarf atmospheric evolution.
2674. Spiral galaxies rotation curve data
ID:
ivo://CDS.VizieR/J/AJ/130/1037
Title:
Spiral galaxies rotation curve data
Short Name:
J/AJ/130/1037
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present new long-slit H{alpha} spectroscopy for 403 non-interacting spiral galaxies, obtained at the Palomar Observatory 5m Hale telescope, which is used to derive well-sampled optical rotation curves. Because many of the galaxies show optical emission features that are significantly extended along the spectrograph slit, a technique was devised to separate and subtract the night sky lines from the galaxy emission. We exploit a functional fit to the rotation curve to identify its center of symmetry; this method minimizes the asymmetry in the final, folded rotation curve. We derive rotational widths using both velocity histograms and the Polyex model fit. The final rotational width is measured at a radius containing 83% of the total light as derived from I-band images.
2675. Spiral potential of the Milky Way
ID:
ivo://CDS.VizieR/J/A+A/619/A50
Title:
Spiral potential of the Milky Way
Short Name:
J/A+A/619/A50
Date:
21 Oct 2021
Publisher:
CDS
Description:
The location of young sources in the Galaxy suggests a four-armed spiral structure, whereas tangential points of spiral arms observed in the integrated light at infrared and radio wavelengths indicate that only two arms are massive. Variable extinction in the Galactic plane and high light-to-mass ratios of young sources make it difficult to judge the total mass associated with the arms outlined by such tracers. The current objective is to estimate the mass associated with the Sagittarius arm by means of the kinematics of the stars across it. Spectra of 1726 candidate B- and A-type stars within 3{deg} of the Galactic center (GC) were obtained with the FLAMES instrument at the VLT with a resolution of ~6000 in the spectral range of 396-457nm. Radial velocities were derived by least-squares fits of the spectra to synthetic ones. The final sample was limited to 1507 stars with either Gaia DR2 parallaxes or main-sequence B-type stars having reliable spectroscopic distances. The solar peculiar motion in the direction of the GC relative to the local standard of rest (LSR) was estimated to U_{sun}_=10.7+/-1.3km/s. The variation in the median radial velocity relative to the LSR as a function of distance from the sun shows a gradual increase from slightly negative values near the sun to almost 5km/s at a distance of around 4kpc. A sinusoidal function with an amplitude of 3.4+/-1.3km/s and a maximum at 4.0+/-0.6kpc inside the sun is the best fit to the data. A positive median radial velocity relative to the LSR around 1.8kpc, the expected distance to the Sagittarius arm, can be excluded at a 99% level of confidence. A marginal peak detected at this distance may be associated with stellar streams in the star-forming regions, but it is too narrow to be associated with a major arm feature. A comparison with test-particle simulations in a fixed galactic potential with an imposed spiral pattern shows the best agreement with a two-armed spiral potential having the Scutum-Crux arm as the next major inner arm. A relative radial forcing dFr~1.5% and a pattern speed in the range of 20-30km/s/kpc yield the best fit. The lack of a positive velocity perturbation in the region around the Sagittarius arm excludes it from being a major arm. Thus, the main spiral potential of the Galaxy is two-armed, while the Sagittarius arm is an inter-arm feature with only a small mass perturbation associated with it.
2676. Spirals in Virgo. III.
ID:
ivo://CDS.VizieR/J/A+AS/110/279
Title:
Spirals in Virgo. III.
Short Name:
J/A+AS/110/279
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the analysis of the rotation curves of a sample of 32 spiral galaxies derived from the spectroscopic observations of a sample of 47 galaxies.
2677. SPIRou wavelength calibration
ID:
ivo://CDS.VizieR/J/A+A/648/A48
Title:
SPIRou wavelength calibration
Short Name:
J/A+A/648/A48
Date:
21 Oct 2021
Publisher:
CDS
Description:
SPIRou is a near-infrared (nIR) spectropolarimeter at the CFHT, covering the YJHK nIR spectral bands (980-2350nm). We describe the development and current status of the SPIRou wavelength calibration in order to obtain precise radial velocities (RVs) in the nIR. We make use of a UNe hollow-cathode lamp and a Fabry-Perot etalon to calibrate the pixel-wavelength correspondence for SPIRou. Different methods are developed for identifying the hollow-cathode lines, for calibrating the wavelength dependence of the Fabry-Perot cavity width, and for combining the two calibrators. The hollow-cathode spectra alone do not provide a sufficiently accurate wavelength solution to meet the design requirements of an internal error of <0.45m/s, for an overall RV precision of 1m/s. However, the combination with the Fabry-Perot spectra allows for significant improvements, leading to an internal error of 0.15m/s. We examine the inter-night stability, intra-night stability, and impact on the stellar RVs of the wavelength solution.
2678. Spitzer Atlas of Stellar Spectra (SASS)
ID:
ivo://CDS.VizieR/J/ApJS/191/301
Title:
Spitzer Atlas of Stellar Spectra (SASS)
Short Name:
J/ApJS/191/301
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Spitzer Atlas of Stellar Spectra (SASS) includes 159 stellar spectra (5 to 32um; R~100) taken with the Infrared Spectrograph (IRS) on the Spitzer Space Telescope. It gathers representative spectra of a broad section of the Hertzsprung-Russell diagram, intended to serve as a general stellar spectral reference in the mid-infrared. It includes stars from all luminosity classes, as well as Wolf-Rayet (WR) objects. Furthermore, it includes some objects of intrinsic interest, like blue stragglers and certain pulsating variables. All the spectra have been uniformly reduced.
2679. Spitzer follow up of 95 brown dwarfs
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.
2680. Spitzer high-resolution MIR spectral atlas
ID:
ivo://CDS.VizieR/J/ApJS/184/230
Title:
Spitzer high-resolution MIR spectral atlas
Short Name:
J/ApJS/184/230
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an atlas of Spitzer/IRS high-resolution (R~600) 10-37um spectra for 24 well known starburst galaxies. The spectra are dominated by fine-structure lines, molecular hydrogen lines, and emission bands of polycyclic aromatic hydrocarbons (PAHs). Six out of the eight objects with a known active galactic nucleus (AGN) component show emission of the high excitation [NeV] line. This line is also seen in one other object (NGC 4194) with, a priori, no known AGN component. In addition to strong PAH emission features in this wavelength range (11.3, 12.7, 16.4um), the spectra reveal other weak hydrocarbon features at 10.6, 13.5, 14.2um, and a previously unreported emission feature at 10.75um. An unidentified absorption feature at 13.7um is detected in many of the starbursts. We use the fine-structure lines to derive the abundance of neon and sulfur for 14 objects where the HI 7-6 line is detected. We further use the molecular hydrogen lines to sample the properties of the warm molecular gas. Several basic diagrams characterizing the properties of the sample are also shown. We have combined the spectra of all the pure starburst objects to create a high signal-to-noise ratio template, which is available to the community.

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