- ID:
- ivo://CDS.VizieR/J/A+A/374/1085
- Title:
- Mg II K line Wilson-Bappu relationship
- Short Name:
- J/A+A/374/1085
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An investigation is carried out on the Wilson-Bappu effect in the MgII K line at 2796.34{AA}. The work is based on a selection of 230 stars observed by both the IUE and HIPPARCOS satellites, covering a wide range of spectral types (F to M) and absolute visual magnitudes (-5.4<=M_V_<=9.0). A semi-automatic procedure is used to measure the line widths, which applies also in the presence of strong central absorption reversal. The Wilson-Bappu relationship here provided is considered to represent an improvement over previous recent results for the considerably larger data sample used, as well as for a proper consideration of the measurement errors. No evidence has been found for a possible dependence of the WB effect on stellar metallicity and effective temperature.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/448/484
- Title:
- MgII UV feature in T Tauri stars
- Short Name:
- J/MNRAS/448/484
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The atmospheric structure of T Tauri stars (TTSs) and its connection with the large-scale outflow is poorly known. Neither the effect of the magnetically mediated interaction between the star and the disc is well understood. The MgII multiplet is a fundamental tracer of TTSs atmospheres and outflows, and is the strongest feature in the near-ultraviolet spectrum of TTSs. The International Ultraviolet Explorer and Hubble Space Telescope data archives provide a unique set to study the main physical compounds contributing to the line profile and to derive the properties of the line formation region. The MgII profiles of 44 TTSs with resolution 13000-30000 are available in these archives. In this work, we use this data set to measure the main observables: flux, broadening, asymmetry, terminal velocity of the outflow, and the velocity of the discrete absorption components. For some few sources repeated observations are available and variability has been studied. There is a warm wind that at sub-au scales absorbs the blue wing of the MgII profiles. The main result found in this work is the correlation between the line broadening, MgII flux, terminal velocity of the flow and accretion rate. Both outflow and magnetospheric plasma contribute to the MgII flux. The flux-flux correlation between MgII and CIV or HeII is confirmed; however, no correlation is found between the MgII flux and the UV continuum or the H_2_ emission.
- ID:
- ivo://CDS.VizieR/J/ApJ/707/482
- Title:
- Models of the solar atmosphere. III.
- Short Name:
- J/ApJ/707/482
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Semiempirical atmospheric models of solar surface features as observed at moderate resolution are useful tools for understanding the observed solar spectral irradiance variations. Paper I described a set of models constructed to reproduce the observed radiance spectrum for solar surface features at ~2 arcsec resolution that constitute an average over small-scale features such as granulation. Paper II showed that a revision of previous models of low-chromospheric inter-network regions explains the observed infrared CO lines in addition to the UV and radio continuum from submillimeter to centimetric wavelengths. The present paper (1) shows that the CaII H and K line wing observations are also explained by the new quiet-Sun-composite model, (2) introduces new low-chromospheric models of magnetic features that follow the ideas in Paper II (Fontenla et al. 2007ApJ...667.1243F), (3) introduces new upper chromospheric structures for all quiet-Sun and active-region models, and (4) shows how the new set of models explains EUV/FUV observations of spectral radiance and irradiance. This paper also discusses the chromospheric radiative-loss estimates in each of the magnetic features. The new set of models provides a basis for the spectral irradiance synthesis at EUV/FUV wavelengths based on the features observed on the solar surface.
- ID:
- ivo://CDS.VizieR/J/A+A/558/A131
- Title:
- Model spectra of hot stars at the pre-SN stage
- Short Name:
- J/A+A/558/A131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the fundamental properties of core-collapse Supernova (SN) progenitors from single stars at solar metallicity. We combine Geneva stellar evolutionary models with initial masses of Mini=20-120M_{sun}_ with atmospheric/wind models using CMFGEN. We provide synthetic photometry and high-resolution spectra of hot stars at the pre-SN stage. For Mini=9-20M_{sun}_, we supplement our analysis using publicly available MARCS model atmospheres of RSGs. We employ observational criteria of spectroscopic classification and find that massive stars, depending on Mini and rotation, end their lives as red supergiants (RSG), yellow hypergiants (YHG), luminous blue variables (LBV), and Wolf-Rayet (WR) stars of the WN and WO spectral types. For rotating models, we obtain the following types of SN progenitors: WO1-3 (Mini<=32M_{sun}_), WN10-11 (25<Mini< 32M_{sun}_), LBV (20<=Mini<25M_{sun}_), G1 Ia+ (18<Mini<20M_{sun}_), and RSGs (9<=Mini<=18M_{sun}_). For non-rotating models, we find spectral types WO1-3 (Mini>40M_{sun}_), WN7-8 (25<Mini<=40M_{sun}_), WN11h/LBV (20<Mini<=25M_{sun}_), and RSGs (9<=Mini<=20M_{sun}_). Our rotating models indicate that SN IIP progenitors are all RSG, SN IIL/b progenitors are 56% LBVs and 44% YHGs, SN Ib progenitors are 96% WN10-11 and 4% WOs, and SN Ic progenitors are all WO stars. We find that not necessarily the most massive and luminous SN progenitors are the brighter ones in a given filter. We show that SN IIP progenitors (RSGs) are bright in the RIJHK_S filters and faint in the UB filters. SN IIL/b progenitors (LBVs and YHGs), and SN Ib progenitors (WNs) are relatively bright in optical/IR filters, while SN Ic progenitors (WOs) are faint in all optical filters. We argue that SN Ib and Ic progenitors from single stars should be undetectable in the available pre-explosion images with the current magnitude limits, in agreement with observational results.
- ID:
- ivo://CDS.VizieR/J/ApJ/864/123
- Title:
- Morphological parameters of galaxies with GALEX
- Short Name:
- J/ApJ/864/123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Evolutionary studies that compare galaxy structure as a function of redshift are complicated by the fact that any particular galaxy's appearance depends in part on the rest-frame wavelength of the observation. This leads to the necessity for a "morphological k-correction" between different passbands, especially when comparing the rest-frame optical or infrared (IR) to the ultraviolet (UV). This is of particular concern for high-redshift studies that are conducted in the rest-frame UV. We investigate the effects of this "bandpass shifting" out of the UV by quantifying nearby galaxy structure via concentration, asymmetry, and clumpiness (CAS) parameters. For this study we combine panchromatic data from the UV through the near-IR with Galaxy Evolution Explorer (GALEX) data of 2073 nearby galaxies in the "near-UV" (NUV; ~230nm) and 1127 in the "far-UV" (FUV; ~150nm), providing the largest study of this kind in the mid- to far-UV. We find a relationship between the CAS parameters and observed rest-frame wavelength that make galaxies appear more late-type at shorter wavelengths, particularly in the UV. The effect is strongest for E/S0 galaxies in the far-UV, which have concentrations and asymmetries that more closely resemble those of spiral and peculiar/merging galaxies in the optical. This may be explained by extended disks containing recent star formation. Here, we also release the CAS values of the galaxies imaged in GALEX NUV and FUV for use in comparisons with deep Hubble Space Telescope imaging and the James Webb Space Telescope in the future.
- ID:
- ivo://CDS.VizieR/J/ApJS/219/15
- Title:
- Morphologies of z=0-10 galaxies with HST data
- Short Name:
- J/ApJS/219/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the redshift evolution of the galaxy effective radius r_e_ obtained from the Hubble Space Telescope (HST) samples of ~190000 galaxies at z=0-10. Our HST samples consist of 176152 photo-z galaxies at z=0-6 from the 3D-HST+CANDELS catalog (Skelton+, 2014, J/ApJS/214/24) and 10454 Lyman break galaxies (LBGs) at z=4-10 identified in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS), HUDF 09/12, and HFF parallel fields, (Harikane+, 2015, in prep) providing the largest data set to date for galaxy size evolution studies. We derive r_e_ with the same technique over the wide redshift range of z=0-10, evaluating the optical-to-UV morphological K correction and the selection bias of photo-z galaxies+LBGs as well as the cosmological surface-brightness dimming effect.
- ID:
- ivo://CDS.VizieR/J/A+A/483/903
- Title:
- Mount Wilson index for main sequence F-K stars
- Short Name:
- J/A+A/483/903
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The largest dataset of stellar activity measurements available at present is the one obtained at the Mount Wilson Observatory, where high-precision CaII H+K fluxes have been measured from 1966 for about 2200 stars. Since the MgII H and K lines at {lambda}2800{AA} are formed in a similar way to the CaII H+K emission lines, they are also good indicators of chromospheric structure. The International Ultraviolet Explorer (IUE) provides a large database of UV spectra in the band 1150-3350{AA} from 1978 to 1995, which can also be used to study stellar activity. The main purpose of this study is to use the IUE spectra in the analysis of magnetic activity of main sequence F-K stars. Combining IUE observations of MgII and optical spectroscopy of CaII, the registry of activity of stars can be extended in time.
- ID:
- ivo://CDS.VizieR/II/269
- Title:
- MSX Ultraviolet Point Source Catalog
- Short Name:
- II/269
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Midcourse Space Experiment (MSX) Ultraviolet Point Source Catalog contains 47,283 point sources from a set of 201 observations that surveyed approximately half the sky and from a set of 32 pointed observations toward specific targets. For each source, we provide position, UV magnitude and uncertainty in at least one of six filters and where possible an identification of a nearby source from the SIMBAD database. If a nearby source is identified, we include its proximity to the MSX source, and if known, the spectral type and the B and V magnitudes of the SIMBAD object. There were 11,565 matches between MSX and SIMBAD objects, and we estimate false identification to be about 3%. The limiting fluxes differ from filter to filter, and range from 10^-16^erg/s/cm2/{AA} for IUN4 to 7.8*10^-12^erg/s/cm2/{AA} for IUW3. Because of variations among the observation sets, the catalog is not complete to the limiting magnitudes for the filters. The UV instrument on MSX was named UVISI (Mill et al., 1994, Journal of Spacecraft and Rockets, 31, 900 (1994JSpRo..31..900M in ADS); Carbary et al., 1994, Applied Optics, 33, 4201 (1994ApOpt..33.4201C in ADS)). The fields-of-view for the narrow-field and wide-field UV imagers were 1.46x1.19deg (detector pixels of 20.6"x17.5") and 13.4x9.2deg (detector pixels of 3.12'x2.27'), respectively. Four filters were used with the narrow-field imager (IUN) with effective wavelengths centered at 2480{AA} (IUN3), 2310{AA} (IUN4), 2230{AA} (IUN5), and 2930{AA} (IUN6). Two filters were used with the wide-field imager (IUW) and centered at 1320{AA} (IUW3) and 1560{AA} (IUW6). Two data files are available for the MSX UV Point Source Catalog: the calibration data file and the catalog data file.
- ID:
- ivo://CDS.VizieR/J/other/RMxAA/35.187
- Title:
- Multifrequency catalog of LINERs
- Short Name:
- J/other/RMxAA/35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first Catalog of Low Ionization Emission Line Galaxies (LINERs or Liners, which is the simplest name, and which we shall adopt in what follows). The Catalog "MCL" (Multifrequency Catalog of Liners), contains 476 entries and contains both broad-band and monochromatic emission data (ranging from radio to X-ray frequencies) of colors, and other data compiled from the literature and various data bases, as indicated in the references. Most of the galaxies can be considered "pure" Liners on the basis of the Veilleux & Osterbrock (1987ApJS...63..295V) classification as suggested by Ho, Filippenko, & Sargent (1997ApJS..112..315H). However, a considerable number of transition (Liners-H II or Liners-Starburst) objects are also included. One of the open questions, is whether Liners should be considered as a class of galaxies (like Seyfert galaxies for instance) or rather, as an heterogeneous group of objects. We believe the study of Liners as a group is very interesting, precisely because they very likely represent a transition between non-thermal and starburst activity, and probably also between "active" and "non- active" galaxies. This catalog may be used as a basis for statistical research. A preliminary discussion of the main statistical properties of Liners, in the range from radio to X-ray frequencies, is given here.
- ID:
- ivo://CDS.VizieR/J/ApJ/862/94
- Title:
- Multiwavelength obs. of GRB 161219B
- Short Name:
- J/ApJ/862/94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present detailed multiwavelength observations of GRB 161219B at z=0.1475, spanning the radio to X-ray regimes, and the first Atacama Large Millimeter/submillimeter Array (ALMA) light curve of a {gamma}-ray burst (GRB) afterglow. The centimeter- and millimeter-band observations before 8.5 days require emission in excess of that produced by the afterglow forward shock (FS). These data are consistent with radiation from a refreshed reverse shock (RS) produced by the injection of energy into the FS, signatures of which are also present in the X-ray and optical light curves. We infer a constant- density circumburst environment with an extremely low density, n_0_~3x10^-4^cm^-3^, and show that this is a characteristic of all strong RS detections to date. The Karl G. Lansky Very Large Array (VLA) observations exhibit unexpected rapid variability on roughly minute timescales, indicative of strong interstellar scintillation. The X-ray, ALMA, and VLA observations together constrain the jet break time, t_jet_~32 days, yielding a wide jet opening angle of {theta}_jet_~13{deg}, implying beaming-corrected {gamma}-ray and kinetic energies of E_{gamma}~4.9x10^48^erg and E_K_~1.3x10^50^erg, respectively. Comparing the RS and FS emission, we show that the ejecta are only weakly magnetized, with relative magnetization, R_B_~1, compared to the FS. These direct, multifrequency measurements of a refreshed RS spanning the optical to radio bands highlight the impact of radio and millimeter data in probing the production and nature of GRB jets.
