- ID:
- ivo://CDS.VizieR/J/AJ/124/3393
- Title:
- Spectra of normal stars in the L-band
- Short Name:
- J/AJ/124/3393
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a brief atlas of L-band (3.3-4.2um) spectra for 42 stars plus the Sun and a sunspot observed at a resolving power of R~3000. This contribution is intended to supplement our previous K-band, H-band, and J-band spectral atlases. The L-band data, which cover some or all of the 2400 to 3000cm^-1^ (3.3-4.2um) region, are mainly for luminous late-type stars. In reducing these data, special care has been taken to remove telluric features, especially water vapor. We identify temperature- and luminosity-sensitive atomic and molecular indices to aid in the classification of stellar spectra in the L band.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/452/567
- Title:
- Spectra of Nova Scuti 2005 N.2 (V477 Sct)
- Short Name:
- J/A+A/452/567
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our CCD photometry of Nova Scuti 2005 N.2 (=V477 Sct) shows it to be a very fast nova, which is characterized by t_2_=3 and t3_=_6 days, affected by a E(B-V)>=1.3mag reddening, and which peaked at V~9.8mag on ~Oct. 12.0 UT. The nova was probably entering a dust condensation episode or brightness oscillations during the transition phase when it became unobservable for the seasonal conjunction with the Sun. Absolute spectrophotometry shows it to belong to the He/N class. The emission line width at half intensity is 2600km/s. At least five ripples are identified in the high resolution emission lines profiles at radial velocities ranging from -980 to +700km/s. The nova erupted at a large distance from the Sun and at an appreciable height above the Galactic plane, suggesting an association with the Galactic bulge (unusual for a He/N nova). The progenitor was too faint to be recorded on DSS1/2 survey plates, when setting the outburst amplitude to DeltaV>=11mag.
2433. Spectra of 12 ON stars
- ID:
- ivo://CDS.VizieR/J/A+A/578/A109
- Title:
- Spectra of 12 ON stars
- Short Name:
- J/A+A/578/A109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Massive stars burn hydrogen through the CNO cycle during most of their evolution. When mixing is efficient or when mass transfer in binary systems occurs, chemically processed material is observed at the surface of O and B stars. ON stars show stronger lines of nitrogen than morphologically normal counterparts. Whether this corresponds to the presence of material processed through the CNO cycle is not known. Our goal is to answer this question. We performed a spectroscopic analysis of a sample of ON stars with atmosphere models. We determined the fundamental parameters as well as the He, C, N, and O surface abundances. We also measured the projected rotational velocities. We compared the properties of the ON stars to those of normal O stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/448/3354
- Title:
- Spectra of quasar narrow-line regions
- Short Name:
- J/MNRAS/448/3354
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In a single optical spectrum, the quasar narrow-line region (NLR) reveals low density, photoionized gas in the host galaxy interstellar medium, while the immediate vicinity of the central engine generates the accretion disk continuum and broad emission lines. To isolate these two components, we construct a library of high S/N optical composite spectra created from the Sloan Digital Sky Survey (SDSS-DR7). We divide the sample into bins of continuum luminosity and H{beta} FWHM that are used to construct median composites at different redshift steps up to 0.75. We measure the luminosities of the narrow-emission lines [NeV]{lambda}3427, [NeIII]{lambda}3870, [OIII]{lambda}5007, and [OII]{lambda}3728 with ionization potentials (IPs) of 97, 40, 35, and 13.6eV respectively. The high IP lines' luminosities show no evidence of increase with redshift consistent with no evolution in the AGN SED or the host galaxy ISM illuminated by the continuum. In contrast, we find that the [OII] line becomes stronger at higher redshifts, and we interpret this as a consequence of enhanced star formation contributing to the [OII] emission in host galaxies at higher redshifts. The SFRs estimated from the [OII] luminosities show a flatter increase with z than non-AGN galaxies given our assumed AGN contribution to the [OII] luminosity. Finally, we confirm an inverse correlation between the strength of the FeII{lambda}4570 complex and both the [OIII] EW (though not the luminosity) and the width of the H{beta} line as known from the eigenvector 1 correlations.
2435. Spectra of 6 SBS stars
- ID:
- ivo://CDS.VizieR/J/A+A/532/A69
- Title:
- Spectra of 6 SBS stars
- Short Name:
- J/A+A/532/A69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Faint high latitude carbon stars are rare objects commonly thought to be distant, luminous giants. For this reason they are often used to probe the structure of the Galactic halo; however more accurate investigation of photometric and spectroscopic surveys has revealed an increasing percentage of nearby objects with luminosities of main sequence stars. We analyzed new optical spectra and photometry and used astronomical databases available on the web, aiming at clarifying the nature of the ten carbon star candidates present in the General Catalogue of the Second Byurakan Survey. We verified that two stars are N-type giants already confirmed by other surveys. We found that four candidates are M-type stars and confirmed the carbon nature of the remaining four stars; the characteristics of three of them are consistent with an early CH giant type. The fourth candidate, SBS 1310+561 identified with a high proper motion star, is a rare type of dwarf carbon showing emission lines in its optical spectrum. We estimated absolute magnitudes and distances to the dwarf carbon and the CH stars. Our limited sample confirmed the increasing evidence that spectroscopy or colour alone are not conclusive luminosity discriminants for CH-type carbon stars.
- ID:
- ivo://CDS.VizieR/J/A+A/440/111
- Title:
- Spectra of SMC star clusters
- Short Name:
- J/A+A/440/111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present flux-calibrated integrated spectra in the range 360-680nm for 18 concentrated SMC clusters. The objects are part of a systematic spectroscopic survey of SMC star clusters which is being undertaken at Complejo Astronomico El Leoncito (CASLEO) in San Juan (Argentina) and Cerro Tololo Inter-American Observatory (CTIO, Chile).
- ID:
- ivo://CDS.VizieR/J/ApJ/900/11
- Title:
- Spectra of SN 2017eaw 545 & 900 days after explosion
- Short Name:
- J/ApJ/900/11
- Date:
- 14 Mar 2022 07:13:15
- Publisher:
- CDS
- Description:
- SN 2017eaw, the tenth supernova observed in NGC6946, was a normal Type II-P supernova with an estimated 11-13M{sun} red supergiant progenitor. Here we present nebular-phase spectra of SN 2017eaw at +545 and +900days post-max, extending approximately 50-400days past the epochs of previously published spectra. While the +545day spectrum is similar to spectra taken between days +400 and +493, the +900day spectrum shows dramatic changes both in spectral features and emission-line profiles. The H{alpha} emission is flat-topped and boxlike with sharp blue and red profile velocities of ~-8000 and +7500km/s. These late-time spectral changes indicate strong circumstellar interaction with a mass-loss shell, expelled ~1700yr before explosion. SN 2017eaw's +900day spectrum is similar to those seen for SN2004et and SN2013ej observed 2-3yr after explosion. We discuss the importance of late-time monitoring of bright SNeII-P and the nature of presupernova mass-loss events for SNII-P evolution.
- ID:
- ivo://CDS.VizieR/J/A+A/414/699
- Title:
- Spectra of southern late-type dwarfs
- Short Name:
- J/A+A/414/699
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Echelle spectra of 91 late-type dwarfs, of spectral types from F to M and of different levels of chromospheric activity, obtained with the 2.15-m telescope of the CASLEO Observatory located in the Argentinean Andes. Our observations range from 3890 to 6690{AA}, at a spectral resolution from 0.141 to 0.249{AA} per pixel (R={lambda}/{delta}{lambda}~26400). The observations were flux calibrated with the aid of long slit spectra (R~1050-2070), also available.
- ID:
- ivo://CDS.VizieR/J/ApJ/887/115
- Title:
- Spectra of 28 stars in Price-Whelan 1 association
- Short Name:
- J/ApJ/887/115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report spectroscopic measurements of stars in the recently discovered young stellar association Price-Whelan 1 (PW1), which was found in the vicinity of the Leading Arm (LA) of the Magellanic Stream (MS). We obtained Magellan+MIKE high-resolution spectra of the 28 brightest stars in PW 1 and used The Cannon to determine their stellar parameters. We find that the mean metallicity of PW1 is [Fe/H]=-1.23 with a small scatter of 0.06dex and the mean RV is V_hel_=276.7km/s with a dispersion of 11.0km/s. Our results are consistent in T_eff_, logg, and [Fe/H] with the young and metal-poor characteristics (116Myr and [Fe/H]=-1.1) determined for PW1 from our discovery paper. We find a strong correlation between the spatial pattern of the PW1 stars and the LA II gas with an offset of -10.15{deg} in L_MS_ and +1.55{deg} in B_MS_. The similarity in metallicity, velocity, and spatial patterns indicates that PW1 likely originated in LA II. We find that the spatial and kinematic separation between LA II and PW1 can be explained by ram pressure from Milky Way (MW) gas. Using orbit integrations that account for the LMC and MW halo and outer disk gas, we constrain the halo gas density at the orbital pericenter of PW1 to be n_halo_(17kpc)=2.7_-2.0_^+3.4^x10^-3^atoms/cm^3^ and the disk gas density at the midplane at 20kpc to be n_disk_(20kpc,0)=6.0_-2.0_^+1.5^x10^-2^atoms/cm^3^. We, therefore, conclude that PW 1 formed from the LA II of the MS, making it a powerful constraint on the MW-Magellanic interaction.
- ID:
- ivo://CDS.VizieR/J/A+A/562/A75
- Title:
- Spectra of 8 supergiants in nearby galaxies
- Short Name:
- J/A+A/562/A75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The role of episodic mass loss in massive star evolution is one of the outstanding questions of current stellar evolution theory. Episodic mass loss produces dust and therefore causes evolved massive stars to be very luminous in the mid-infrared and dim at optical wavelengths. We aim to increase the number of investigated luminous mid-IR sources to shed light on the late stages of these objects. To achieve this we explore mid-IR selection criteria to identity dusty evolved massive stars in two nearby galaxies. The method is based on mid-IR colors, using 3.6um and 4.5um photometry from archival Spitzer Space Telescope images of nearby galaxies and J-band from 2MASS. We apply our criteria to two nearby star-forming dwarf-irregular galaxies: Sextans A and IC 1613, selecting 8 targets, which we follow up with spectroscopy. Our spectral classification and analysis yielded the discovery of 2 M-type supergiants in IC 1613, 3 K-type supergiants and 1 candidate F-type giant in Sextans A, and 2 foreground M giants. We show that the proposed criteria provide an independent way for identifying dusty evolved massive stars, which can be extended to all nearby galaxies with available Spitzer/IRAC images at 3.6um and 4.5um.
