- ID:
- ivo://CDS.VizieR/J/A+A/619/A152
- Title:
- Variation of MgHe line profile with temperature
- Short Name:
- J/A+A/619/A152
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Line shapes of the magnesium resonance lines in white dwarf spectra are determined by the properties of magnesium atoms and the structure of the white dwarf atmosphere. Through their blanketing effect, these lines have a dominant influence on the model structure and thus on the determination from the spectra of other physical parameters that describe the stellar atmosphere and elemental abundances. In continuation of previous work on Mg+He lines in the UV, we present theoretical profiles of the resonance line of neutral Mg perturbed by He at the extreme density conditions found in the cool largely transparent atmosphere of DZ white dwarfs. We accurately determined the broadening of Mg by He in a unified theory of collisional line profiles using ab initio calculations of MgHe potential energies and transition matrix elements among the singlet electronic states that are involved for the observable spectral lines. We computed the shapes and line parameters of the Mg lines and studied their dependence on helium densities and temperatures. We present results over the full range of temperatures from 4000 to 12000K needed for input to stellar spectra models. Atmosphere models were constructed for a range of effective temperatures and surface gravities typical for cool DZ white dwarfs. We present synthetic spectra tracing the behavior of the Mg resonance line profiles under the low temperatures and high gas pressures prevalent in these atmospheres. The determination of accurate opacity data of magnesium resonance lines together with an improved atmosphere model code lead to a good fit of cool DZ white dwarf stars. The broadening of spectral lines by helium needs to be understood to accurately determine the H/He and Mg/He abundance ratio in DZ white dwarf atmospheres. We emphasize that no free potential parameters or ad hoc adjustments were used to calculate the line profiles.
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Search Results
- ID:
- ivo://CDS.VizieR/III/256
- Title:
- Vatican Emission-line stars
- Short Name:
- III/256
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The survey represents a search for H{alpha} emission-line stars, and was conducted with a 12{deg} objective prism on the Vatican Schmidt telescope. The Vatican Emission Stars (VES) survey covers the galactic plane (|b|<=5{deg}) between galactic longitudes 58 and 174{deg}. The catalog was re-examined by B. Skiff (Lowell Observatory), and tne VES stars were cross-identified with modern surveys: GSC (Cat. I/255), Tycho-2 (I/256), 2MASS (II/246), IRAS point source catalog (II/125), MSX6C (V/114), CMC14 (I/304), GSC-2.3 (I/305), UCAC2 (I/289). Cross-identifications are also supplied with HD/BD/GCVS names, and with Dearborn catalog of red stars (II/68). Many of the stars in the first four papers are not early-type emission-line stars, but instead M giants, where the sharp TiO bandhead at 6544{AA} was mistaken for H-{alpha} emission on the objective-prism plates. Based on the revision of paper V and a later list prepared by Jack MacConnell, a column identifies the "non H-alpha" stars explicitly. The links with the Dearborn, IRAS, and MSX catalogues help identify the red stars. These and other identifications and comments are given in the remarks at the end of each line, or in longer notes in a separate file, indicated by an asterisk (*) next to the star number.
- ID:
- ivo://CDS.VizieR/J/ApJ/887/135
- Title:
- V-band, 5100{AA} and broad emission LCs of Mrk 79
- Short Name:
- J/ApJ/887/135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We developed a spectroscopic monitoring project to investigate the kinematics of the broad-line region (BLR) in active galactic nuclei (AGNs) with ultrafast outflows (UFOs). Mrk 79 is a radio-quiet AGN with UFOs and warm absorbers and has been monitored by three reverberation mapping (RM) campaigns, but its BLR kinematics are not yet understood. In this paper, we report the results from a new RM campaign of Mrk 79, which was undertaken with the Lijiang 2.4m telescope. Mrk 79 appears to come out the faint state, with the mean flux approximately a magnitude fainter than the historical record. We successfully measured the lags of the broad emission lines including H{beta}{lambda}4861, H{gamma}{lambda}4340, HeII{lambda}4686, and HeI{lambda}5876 with respect to the varying AGN continuum. Based on the broad H{beta}{lambda}4861 line, we measured a black hole mass of M_{bullet}_=5.13_-1.55_^+1.57^x10^7^M_{sun}_, and an estimated accretion rate of dM/dt_{bullet}_=(0.05+/-0.02)L_Edd_c^-2^, indicating that Mrk 79 is a sub-Eddington accretor. We found that Mrk 79 deviates from the canonical Radius-Luminosity relationship. The marginal blueshift of the broad HeII{lambda}4686 line detected from the rms spectrum indicates outflow of high- ionization gas. The velocity-resolved lag profiles of the broad H{gamma}{lambda}4340, H{beta}{lambda}4861, and HeI{lambda}5876 lines show similar signatures such that the largest lag occurs in the red wing of the lines and then the lag decreases to both sides. These signatures may suggest that the BLR of Keplerian motion probably exists as outflow gas motion. All findings including UFOs, warm absorbers, and the kinematics of high- and low-ionization BLR, may provide indirect evidence that the BLR of Mrk 79 probably originates from a disk wind.
- ID:
- ivo://CDS.VizieR/J/ApJ/732/121
- Title:
- V-band and H{beta} monitoring of Z299-15
- Short Name:
- J/ApJ/732/121
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Seyfert 1 galaxy Zw 229-015 is among the brightest active galaxies being monitored by the Kepler mission. In order to determine the black hole mass in Zw 229-015 from H{beta} reverberation mapping, we have carried out nightly observations with the Kast Spectrograph at the Lick 3m telescope during the dark runs from 2010 June through December, obtaining 54 spectroscopic observations in total. We have also obtained nightly V-band imaging with the Katzman Automatic Imaging Telescope at Lick Observatory and with the 0.9m telescope at the Brigham Young University West Mountain Observatory over the same period. We detect strong variability in the source, which exhibited more than a factor of two change in broad H{beta} flux. From cross-correlation measurements, we find that the H{beta} light curve has a rest-frame lag of 3.86^+0.69^_-0.90_ days with respect to the V-band continuum variations. We also measure reverberation lags for H{alpha} and H{gamma} and find an upper limit to the H{delta} lag. Combining the H{beta} lag measurement with a broad H{beta} width of {sigma}_line_=1590+/-47km/s measured from the rms variability spectrum, we obtain a virial estimate of M_BH_=1.00^+0.19^_-0.24_x10^7^M_{sun}_ for the black hole in Zw 229-015.
- ID:
- ivo://CDS.VizieR/J/ApJ/846/115
- Title:
- V-band photometry and RVs of V482 Persei system
- Short Name:
- J/ApJ/846/115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report spectroscopic and differential photometric observations of the A-type system V482 Per, which reveal it to be a rare hierarchical quadruple system containing two eclipsing binaries. One binary has the previously known orbital period of 2.4 days and a circular orbit, and the other a period of 6 days, a slightly eccentric orbit (e=0.11), and shallow eclipses only 2.3% deep. The two binaries revolve around their common center of mass in a highly elongated orbit (e=0.85) with a period of 16.67yr. Radial velocities are measured for all components from our quadruple-lined spectra and are combined with the light curves and measurements of times of minimum light for the 2.4 day binary to solve for the elements of the inner and outer orbits simultaneously. The line-of-sight inclination angles of the three orbits are similar, suggesting they may be close to coplanar. The available observations appear to indicate that the 6 day binary experiences significant retrograde apsidal motion in the amount of about 60 deg per century. We derive absolute masses for the four stars good to better than 1.5%, along with radii with formal errors of 1.1% and 3.5% for the 2.4 day binary and ~9% for the 6 day binary. A comparison of these and other physical properties with current stellar evolution models gives excellent agreement for a metallicity of [Fe/H]=-0.15 and an age of 360Myr.
- ID:
- ivo://CDS.VizieR/J/A+A/565/L7
- Title:
- V1180 Cas outburst optical and NIR spectra
- Short Name:
- J/A+A/565/L7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the ongoing outburst of the young variable V1180 Cas, which is known to display characteristics in common with EXor eruptive variables. We present results that support the scenario of an accretion-driven nature of the brightness variations of the object and provide the first evidence of jet structures around the source. We monitored the recent flux variations of the target in the R_C_, J, H, and K bands. New optical and near-IR spectra taken during the current high state of V1180 Cas are presented, in conjunction with H_2_ narrow-band imaging of the source.
- ID:
- ivo://CDS.VizieR/J/AJ/131/814
- Title:
- VCC 1087 globular cluster system
- Short Name:
- J/AJ/131/814
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of the globular cluster (GC) system of the nucleated dwarf elliptical galaxy VCC 1087 in the Virgo Cluster based on Keck LRIS spectroscopy and archival Hubble Space Telescope Advanced Camera for Surveys imaging. We estimate that VCC 1087 hosts a total population of 77+/-19 GCs, which corresponds to a relatively high V-band specific frequency of 5.8+/-1.4. The g_475_-z_850_ color distribution of the GCs shows a blue (metal-poor) peak with a tail of redder (metal-rich) clusters similar in color to those seen in luminous elliptical galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/420/571
- Title:
- V1974 Cyg IUE spectroscopy
- Short Name:
- J/A+A/420/571
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out a detailed analysis of the IUE archival high resolution spectra of the classical nova V1974 Cyg 1992. The main UV resonance lines show P Cygni profiles in the first days, which change into symmetric pure emission lines, and then slowly become fainter and narrower. Lines of higher ionization species reach their peak luminosity later than those of low ionization.
- ID:
- ivo://CDS.VizieR/J/PAZh/41/665
- Title:
- V1016 Cyg light curves and spectroscopy
- Short Name:
- J/PAZh/41/665
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As a result of the next cycle of our long-term monitoring, we present our UBV JHKLM photometry for the symbiotic nova V1016 Cyg in 2008-2014. The star continued to systematically fade and redden in UBV: over this period, the brightness declined by 0.1m in V and by 0.2m in B and U ,the B-V color index increased by 0.1m, and U-B barely changed. On the color-color (U-B, B-V) diagram, the star moved approximately horizontally rightward with a slight bluing in U-B starting from 2000. Our JHKLM photometry has shown a decline in the mean infrared (IR) brightness and a rise in the mean IR color indices after 2004 due to an increase in the optical depth of the dust envelope. The brightness decline and reddening of the Mira in the near infrared reached their extreme values over the entire period of the system's observations by the end of 2014. The pulsation period of the Mira is determined with confidence: P=465+/-5-days. The distance to the Mira, D=2.92+/-0.16kpc, ant its parameters, the radius R*=(470+/-50)R_{sun}_ and luminosity L*=(9200+/=1900)L_{sun}_, have been estimated from the observations of V1016 Cyg at its maximum J brightness and at its minimum J-H color index. The temperature of the star during its pulsations varied within the range T* =2100-2700K. We have estimated the parameters of the dust envelope near its maximum (in 2004) and minimum (in 2012-2014) IR brightness. The mass of the dust envelope almost doubled in ten years, with the rate of dust supply being {Delta}Md~10^-7^M_{sun}_/yr. Using a low-resolution spectrograph, we performed absolute spectrophotometry for V1016 Cyg in 1995-2013 in the range {lambda}4340-7130{AA}. We have shown that almost all absolute fluxes in lines and in continuum at {lambda}4400{AA} decrease monotonically after 2000, while the relative intensities of [OIII], [FeVII], and [CaVII] lines increase after the minimum that probably occurred in the 1990s. The significant (approximately by a factor of 10 from 1995 to 2013) decrease of the flux in the Raman OVI {lambda}6825 line reflects a change of conditions in the formation zone of this line due to the absorption of some OVI {lambda}1032 photons in the newly forming dust envelope of the cool component.
- ID:
- ivo://CDS.VizieR/J/A+A/600/A96
- Title:
- V407 Cyg spectral variations
- Short Name:
- J/A+A/600/A96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The outburst of the symbiotic recurrent nova V407 Cyg in 2010 has been studied by numerous authors. On the other hand, its spectral variations in the quiescent stage have not been well studied yet. This paper is probably the first report for the relation between the pulsation of the secondary Mira variable and the temperature of the primary hot component for V407 Cyg. The spectral variation in the post-outburst stage has been monitored to study the properties of this object. In the course of this work, we found some unexpected spectral variations around the light maximum of the secondary Mira variable in 2012. The relation between the mass transfer in the binary system and the pulsation of the secondary Mira variable is studied. High- and low-resolution optical spectra obtained at the Astronomical Observatories at Asiago were used. The photometric data depend on the database of the VSNET.
