Analysis of the Emission Line Spectrum of V380 Ori and HD45677

Muratorio, G.; Rossi, C.; Friedjung, M.; Viotti, R.

doi:10.1007/978-94-015-9014-3_16

Cited by 9 publications

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“…It then carries information on the optical depth regime that controls the Fe ii line emission formation in the CE of Be stars. The SAC method has been successfully applied to studying CE in a number of different types of objects: luminous blue stars (Muratorio & Friedjung 1988, Muratorio et al 1992, B[e] stars (Muratorio et al 2002a), P Cygni (Muratorio et al 2002b), novae (Selvelli & Friedjung 2003), symbiotic stars (Kotnik-Karuza et al 2002), the Be star component in Z CMa (van den Ancker 2004), etc. In this paper, we use the SAC method to determine the optical depth regime of Fe ii emission lines observed in 17 Be classical stars and to estimate the extent of their formation region in the CE (HD 164284 has Fe ii lines too small to be measured reliably).…”

Section: The Sac Methodsmentioning

confidence: 99%

Fe II emission lines in Be stars

Arias

Zorec

Cidale

et al. 2006

A&A

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Aims. The Fe ii emission lines formed in the circumstellar envelopes (CE) of classical Be stars are studied in order to determine whether they are optically thin or optically thick. We also aim at deriving both average Fe ii line excitation temperatures and the extent of their formation region in the CE.Methods. We simultaneously observed several series of Fe ii emission lines in the λλ4230−7712 Å wavelength interval and the first members of the hydrogen Balmer series of 18 southern classical Be stars. The optical depth regime that controls the formation of the observed Fe ii lines and the physical parameters of their CE formation region were studied using the empirical self-aborption-curve (SAC) method.Results. Our calculations give an average value of τ o = 2.4 ± 0.9 for the optical depth of the studied Fe ii lines, which implies that these lines are optically thick in the CE of Be stars. Qualitative indications that Fe ii emission lines should be formed in circumstellar regions close to the central star are inferred from the correlations between Fe ii emission line widths and V sin i. The application of the SAC method to Fe ii emission lines confirms this result, which gives R e = 2.0R * ± 0.8 for the extension of the line-forming region. The proximity of the line-forming region to the central star is also supported by the behavior of the source function of Fe ii lines, which rapidly decreases with radii. This prevents the lines from being formed over extended regions and/or far from the star. Finally, the correlations of the central depression in the Balmer emission lines with V sin i are consistent with the flattened geometrical shapes of CEs.

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Section: The Sac Methodsmentioning

confidence: 99%

Fe II emission lines in Be stars

Arias

Zorec

Cidale

et al. 2006

A&A

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“…Here we analyse the intensity of the permitted and forbidden ionized iron emission lines and permitted ionized chromium emission lines in a statistical way, the Self-Absorption-Curve Method (SAC), following the procedure described by Friedjung & Muratorio (1987), and used among others by Muratorio et al (1992), Viotti et al (1999), Viotti et al (2000), Kotnik-Karuza et al (2002) and van den Ancker et al (2004). Details on the SAC method are given in the SAC Manual (Baratta et al 1998, available at www.rm.iasf.cnr.it/ftp/uvspace/).…”

Section: Analysis Of the Emission Line Fluxesmentioning

confidence: 99%

Analysis of the circumstellar environment of the B[ e] star HD 45677 (FS Canis Majoris)

Muratorio¹,

Rossi²,

Friedjung³

2006

A&A

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Aims. We studied the circumstellar environment of the B[e] star HD 45677 through the analysis of the emission lines from ionized metals. Methods. We used the statistical approach of the self absorption curve method (SAC) to derive physical parameters of the line emitting region. Results. The Fe II and Cr II double-peaked emission line structure is explained by the presence of a thin absorption component red shifted by ∼3 km s −1 . This absorption component can be interpreted geometricaly as being due to infalling material perpendicularly to the disk seen nearly pole-on, as indicated by the emission line structure. The Cr II and Fe II emission lines have a complex structure with two (narrow and broad) components, of 45 and 180 km s −1 FWHM for the permitted lines and 25 and 100 km s −1 FWHM for the forbidden ones, respectively. From our best data set of 1999, we obtained a Boltzmann-type population law whose excitation temperature is 3900 +900 −600 K and 3150 +350−300 K for the narrow component lower and upper levels respectively. We obtained an excitation temperature of 3400 +350 −300 K for the broad component upper levels. The forbidden lines are found to be formed in the outer regions with higher excitation temperatures of 10 500 ± 1000 K and 8000 ± 1500 K for the narrow and broad components respectively in 1999. Our results are consistent with line formation in a rotating disk, around a young star. In the framework of a very simplified geometrical model, we argue that the narrow components are principaly emitted by an optically thin disk seen nearly pole-on, in a region whose minimum radius is estimated to be 4×10 12 cm, while the broad ones are formed in a disk-linked wind.

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“…These values are about three times larger with respect to the theoretical flux of 2.5 10 −12 erg cm −2 s −1 , computed according to the Self-Absortion-Curve analysis of the Fe ii lines in the 1979 UV spectrum of KQ Pup made by Muratorio et al (1992). This difference should be accounted for by the anomalous strength of the high excitation Fe ii emission lines as noted by Muratorio et al (1992). It might also be at least partly due to the gradual increase of the line emission when the KQ Pup system is approaching the periastron (Cowley 1965).…”

Section: The Vv Cep Star Kq Pupmentioning

confidence: 66%

“…In the framework of many observing programmes we have collected high resolution spectra of many emission line objects belonging to different stellar categories, and some results have beeen published on particular stars and projects (e.g. Rossi et al 1988;Rossi et al 1991;Altamore et al 1992;Muratorio et al 1992;Viotti et al 1992Viotti et al , 1994, but the quantity of information that can be extracted from a single spectrum is often much wider than that used for a given project. For this reason we reanalysed from a different point of view some old spectra of ours, to which new ones have been added.…”

Section: Introductionmentioning

confidence: 99%

Optical and near-IR observations of variable stars with AURELIE

Viotti

Rossi

Muratorio³

1998

Astron. Astrophys. Suppl. Ser.

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Abstract. We report high and intermediate resolution spectroscopic observations of many emission line stars mainly observed with Aurélie at the 1.52 m OHP telescope in December 1990 and January 1995, with special attention to the Hα and 1 µm regions. The near-IR observations of the Be star γ Cas disclosed the presence of a very strong fluorescence Fe ii 1.00 µm emission, with intensity and profile similar to that of Pδ. Both have varied between 1990 and 1995. The Fe ii 1.00 µm line is also weakly present in emission in β Ori, and in the 1990 and 1995 spectra of the VV Cep star KQ Pup. The high resolution 1995 observations of the yellow hypergiant HR 8752 disclosed a broad [N ii] emission, and Hα with multiple components. The slow approaching of the KQ Pup system to periastron is marked by the large strengthening of the Hα emission between 1984 and 1995. Strong variation in Hα intensity was also found in the yellow symbiotic star AG Dra observed in quiescence and during its recent active phase. The red symbiotic star CH Cyg was especially interesting for the large profile variation of the Balmer lines on a daily time scale in January 1995. We detected expansion velocities of up to 2000 km s −1 . In December 1990 the yellow spectrum of CH Cyg displayed a broad He i 587 nm absorption, which turned to strong emission in 1995. We also report observations of π Aqr, R Aqr, EZ CMa, β CMi, and HD 200775.

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Analysis of the Emission Line Spectrum of V380 Ori and HD45677

Cited by 9 publications

References 0 publications

Fe II emission lines in Be stars

Fe II emission lines in Be stars

Analysis of the circumstellar environment of the B[ e] star HD 45677 (FS Canis Majoris)

Optical and near-IR observations of variable stars with AURELIE

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