J/A+A/317/712       UV fluxes and electron density of AG Peg (Altamore+ 1997)

The 1978-1995 variability of the symbiotic star AG Pegasi in the ultraviolet Altamore A., Cassatella A. <Astron. Astrophys. 317, 712 (1997)> =1997A&A...317..712A 1997A&A...317..712A (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, cataclysmic ; Spectra, ultraviolet ; Energy distributions Keywords: stars: individual: AG Peg - cataclysmic variables - binaries: symbiotic - ultraviolet: stars - line: profile Description: In this paper we study in detail the variability of the symbiotic nova AG Peg in the IUE range during the period 1978-1995. We find that the luminosity of the hot component decreased steadily from about 1850L in 1978 to 430L in 1995 while its effective temperature remained nearly constant, 86500±1300K. At the same time, the mass loss rate decreased by a factor of 4-5 although the ejection velocity remained constant. The observed fainting of both the narrow and the broad emission lines is ascribed to the decrease of the luminosity and ionizing flux from the hot source. The narrow emission lines and the long wavelength UV continuum show periodic variations arising from a dense and asymmetric nebular region associated with the cool star. Radial velocity variations of the narrow lines indicate that this region is receding from the center of mass of the system, and support the presence of the ablation tail suggested by Penston and Allen (1985MNRAS.212..939P 1985MNRAS.212..939P). No periodic flux variations are seen in the short wavelength ultraviolet continuum and in the broad emission lines, which are both formed in the fast wind from the hot component. Objects: ----------------------------------------- RA (2000) DE Designation(s) ----------------------------------------- 21 51 01.9 +12 37 32 AG Peg ----------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table2 30 34 FES magnitudes and UV fluxes table2.tex 62 189 TeX version of table2 table3a 23 34 Electron density from the [SiIII]/[CIII] ratio table3a.tex 60 152 TeX version of table3a table3b 28 15 Electron density from the [N III] multiplet table3b.tex 62 111 TeX version of table3b table4 36 57 Radial velocities of the UV emission lines table4.tex 75 208 TeX version of table4 table5 32 31 HeII Zanstra temperatures table5.tex 68 181 TeX version of table5 -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2 -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 7 I7 d HJD Julian date 9- 12 F4.2 mag FESmag ? Fine Error Sensor magnitude 14- 18 F5.2 10-15W/m2/nm F1455 ? Observed flux at 1455 A (1) 20- 24 F5.2 10-15W/m2/nm F1835 ? Observed flux at 1835 A (1) 26- 30 F5.2 10-15W/m2/nm F2855 ? Observed flux at 2855 A (1) -------------------------------------------------------------------------------- Note (1): Fluxes are in 10**(-13) erg/cm2/s/A. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table3a -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 7 I7 d HJD Julian date 9- 12 F4.2 10-14W/m2 FSiIII Observed flux of SiIII] 1893 A line (1) 14- 17 F4.2 10-14W/m2 FCIII Observed flux of CIII] 1909 A line (1)9 19- 23 F5.2 [cm-3] log(Ne) Decimal log of electron density -------------------------------------------------------------------------------- Note (1): Fluxes are in 10**(-11) erg/cm2/s -------------------------------------------------------------------------------- Byte-by-byte Description of file: table3b -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 7 I7 d HJD Julian date 9- 12 F4.2 10-14W/m2 F1748.6 Observed flux of N III] 1748.6 A line (1) 14- 17 F4.2 10-14W/m2 F1749.5 Observed flux of N III] 1749.5 A line (1) 19- 22 F4.2 10-14W/m2 F1754.0 Observed flux of N III] 1754.0 A line (1) 24- 28 F5.2 [cm-3] log(Ne) Decimal log of electron density -------------------------------------------------------------------------------- Note (1): Fluxes are in 10**(-11) erg/cm2/s -------------------------------------------------------------------------------- Byte-by-byte Description of file: table4 -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 7 I7 d HJD Julian date 9- 14 F6.2 km/s HRV ? Mean heliocentric radial velocity of the CIII] and SiIII] lines 16- 19 F4.2 km/s e_HRV ? rms uncertainty on HRV1 22- 27 F6.2 km/s RV1 ? Radial velocity of the HeII 1640A emission line 31- 36 F6.2 km/s RV2 ? Radial velocity of the NIV] 1487A emission line -------------------------------------------------------------------------------- Byte-by-byte Description of file: table5 -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1 A1 --- Note [HL] H: High resolution data, L: Low resolution data 3- 9 I7 d HJD Julian date 11- 15 F5.2 10-14W/m2 F1640 Flux of the HeII 1640A line (1) 17- 20 F4.2 10-13W/m2/nm F1335 Flux of the continuum around 1335A (2) 22- 26 F5.2 --- F1640/F1335 Ratio of F1640 to F1335 28- 32 I5 K T Zanstra temperature -------------------------------------------------------------------------------- Note (1): Fluxes are in 10**(-11) erg/cm2/s Note (2): Fluxes are in 10**(-11) erg/cm2/s/A -------------------------------------------------------------------------------- Acknowledgements: Angelo Cassatella
(End) Patricia Bauer [CDS] 06-Nov-1996
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