J/A+A/532/A138      V838 Mon spectrum in 2009                 (Tylenda+, 2011)

High-resolution optical spectroscopy of V838 Monocerotis in 2009. Tylenda R., Kaminski T., Schmidt M., Kurtev R., Tomov T. <Astron. Astrophys. 532, A138 (2011)> =2011A&A...532A.138T 2011A&A...532A.138T
ADC_Keywords: Spectroscopy ; Stars, peculiar ; Stars, late-type Keywords: stars: individual: V838 Mon - stars: late-type - stars: peculiar Abstract: V838 Mon erupted at the beginning of 2002. In the course of the outburst the object evolved to low effective temperatures and declined as a very late M-type supergiant. Among various scenarios proposed to explain the nature of the outburst, the most promising is a stellar merger event. We aim at studying the structure and evolution of the object in the decline from the 2002 eruption. We obtained spectroscopic observations of V838 Mon in January-March 2009 with UVES/VLT. The results are analysed and compared with similar observations obtained in October 2005 with HIRES/Keck. The most striking difference between 2009 and 2005 is a complete absence of the B3 V component and of the [FeII] emission lines in 2009. The present spectrum displays only the spectrum of the 2002 eruption remnant. It resembles that of an ∼M6 giant, although the molecular bands in V838 Mon are deeper than those in standard stellar spectra of a similar spectral class. Several atomic lines, which displayed P-Cyg profiles in 2005, are now dominated by pure absorptions. Some of these lines, however, show a narrow emission component, which, as we argue, measures the radial velocity of V838 Mon. The resulting heliocentric velocity is 71km/s, which very well agrees with the velocity obtained from SiO maser observations. The atomic lines and the molecular bands show very complex kinematics. In some atomic lines and high-excitation molecular bands we observe matter infalling in the object atmosphere. The infall components were already observed in 2005, but were less pronounced and present in fewer lines than in 2009. We argue that the most negative radial velocity components seen in the resonance atomic lines and in the low-excitation molecular bands were formed in the ejecta of the 2002 eruption. The B3V companion most probably became engulfed in an opaque dusty matter of the 2002 V838 Mon ejecta. Description: This data set consists of three spectra of V838 Mon obtained with UVES at VLT on 2 Jan., 13 Feb., and 22 March 2009. The spectra were acquired in the UVES standard red arm 580 setting, which gives a spectral coverage of 4770-6825 Angstroms. The spectral resolution is around R=52,000. Spectra are NOT corrected for the interstellar extinction and the wavelength scale corresponds to heliocentric rest frame. The flux density unit is erg/s/cm2/Å, wavelength is in Angstroms. Average spectrum of three spectra obtained with UVES/VLT in January, February and March 2009. Before averaging the spectra were shifted to the heliocentric rest frame and calibrated in flux. Deredenned version of this spectrum is presented with black line in Figure 1 of the paper. Objects: ----------------------------------------------------- RA (2000) DE Designation(s) ----------------------------------------------------- 07 04 04.8 -03 50 51 V838 Mon = NOVA Mon 2002 ----------------------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file v838mon.dat 30 105836 Averaged spectrum of V838 Mon 0201flx.dat 30 105782 Spectrum from 02 January 2009 1302flx.dat 30 105789 Spectrum from 13 February 2009 2203flx.dat 30 105736 Spectrum form 22 March 2009 -------------------------------------------------------------------------------- See also: J/PAZh/28/764 : UBVR photometry of Nova Mon 2002 (V838 Mon) (Goranskii+, 2002) J/ApJ/598/L43 : Polarimetry of V838 Mon and stars around (Wisniewski+, 2003) J/AZh/84/147 : Light curves of V838 Mon and V4332 Sgr (Goranskii+, 2007) Byte-by-byte Description of file: *.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 16 F16.11 0.1nm lambda Wavelength in heliocentric rest frame 18- 30 E13.6 10mW/m2/nm Flux Observed absolute flux (erg/s/cm2/Å) -------------------------------------------------------------------------------- Acknowledgements: Romuald Tylenda, tylenda(at)ncac.torun.pl Tomasz Kaminski, tomkam(at)ncac.torun.pl
(End) R. Tylenda, T. Kaminski [NCAC, Poland], P. Vannier [CDS] 08-Jul-2011
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