Lithium in the symbiotic Mira V407 Cyg

Tatarnikova, A. A.; Marrese, P. M.; Munari, U.; Tomov, T.; Whitelock, P. A.; Yudin, B. F.

doi:10.1046/j.1365-8711.2003.06911.x

Cited by 21 publications

(18 citation statements)

References 26 publications

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“…The Mira has a long pulsation period and based on the Munari et al (1990) radius, 400 R , it must not be filling its Roche surface. If the strong Li I line is evidence of hot bottom burning, as argued by Tatarnikova et al (2003b) (see also Herwig 2005 for a general review), then its mass must be greater than 4 M . Assuming that the WD is as massive as in RS Oph, around 1.2 M , then using the scaling from Eggleton (1983) for the ratio of the Roche radius, R RL , to the semimajor axis, a, gives R RL /a ≈ 0.3 for a mass ratio of ≥3.…”

Section: Discussion: Toward a Model Of The Outburst And The Binary Symentioning

confidence: 95%

The spectroscopic evolution of the symbiotic-like recurrent nova V407 Cygni during its 2010 outburst

Shore

Wahlgren

Augusteijn

et al. 2011

A&A

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Context. V407 Cyg was, before 2010 Mar., known only as a D-type symbiotic binary system in which the Mira variable has a pulsation period of approximately 750 days, one of the longest known. On 2010 Mar. 10, it was discovered in outburst, eventually reaching V < 8. This is the first recorded nova event for this system, but it closely resembles the spectroscopic development of RS Oph, the prototypical symbiotic-like recurrent nova. It was also detected by Fermi above 100 MeV and displayed strong, likely nonthermal centimeter wavelength radio emission. Aims. Unlike classical novae occurring in compact cataclysmic binary systems, for which the ejecta undergo free ballistic expansion, this explosion occurred within the dense, complex wind of a Mira variable companion. This paper concentrates on the development of the shock and its passage through the Mira wind. We also present some constraints on the binary system properties. Methods. Using medium and high resolution ground-based optical spectra, visual and Swift UV photometry, and Swift X-ray spectrophotometry, we describe the behavior of the high-velocity profile evolution for this nova during its first three months. Results. Using the diffuse interstellar bands visible in the high-resolution optical spectra, we obtain an extinction E(B − V) ≈ 0.45 ± 0.05. The spectral type of the red giant during this period, when the star was at R minimum, was no earlier than M7 III. The peak of the X-ray emission occurred at about day 40 with a broad maximum and decline after day 50. The main changes in the optical spectrum began at around that time. The He II 4686 Å line first appeared between days 7 and 14 and initially displayed a broad, symmetric profile that is characteristic of all species before day 60. The profile development thereafter depended on ionization state. Low-excitation lines remained comparatively narrow, with v rad,max of order 200-400 km s −1 . They were systematically more symmetric than lines such as [Ca V], [Fe VII], [Fe X], and He II, all of which showed a sequence of profile changes going from symmetric to a blue wing similar to that of the low ionization species but with a red wing extended to as high as 600 km s −1 . The [O I] 6300, 6364 doublet showed a narrow wind-emission component near the rest velocity of the system and a broad component, 200-300 km s −1 , whose relative intensity increased in time. Forbidden lines of N II and O III had two separate contributors to the profiles, a broad line that increased in strength and velocity width, exceeding 200 km s −1 , and narrow components from a surrounding ionized region at higher velocity than the Mira wind. The Na I D doublet developed a broad component with similar velocity width to the other low-ionization species. The O VI Raman features observed in recent outbursts of RS Oph were not detected. We interpret these variations as aspherical expansion of the ejecta within the Mira wind. The blue side is from the shock penetrating into the wind while the red wing is from the low-density peri...

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Section: Discussion: Toward a Model Of The Outburst And The Binary Symentioning

confidence: 95%

The spectroscopic evolution of the symbiotic-like recurrent nova V407 Cygni during its 2010 outburst

Shore

Wahlgren

Augusteijn

et al. 2011

A&A

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show abstract

“…The chromospheric lines, and the "emission 10 There is an ambiguity here. Deguchi et al give the system heliocentric radial velocity of −41 km s −1 , and discuss orbital motion with a 43 year period citing the radial velocity from Tatarnikova et al (2003b) using the Ca I 6573 Å line. We detected this line in the last NOT spectra from 2010 and in the 2011 spectrum at v rad = −43 km s −1 .…”

Section: Discussion: the Circumstellar Environment Of The V407 Cyg Symentioning

confidence: 99%

The spectroscopic evolution of the symbiotic-like recurrent nova V407 Cygni during its 2010 outburst

Shore

Wahlgren

Augusteijn

et al. 2012

A&A

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Context. The nova outburst of V407 Cyg in 2010 Mar. 10 was the first observed for this star but its close resemblance to the well known symbiotic-like recurrent nova RS Oph suggests that it is also a member of this rare type of Galactic novae. The nova was the first detected at γ-ray energies and is the first known nova explosion for this system. The extensive multiwavelength coverage of this outburst makes it an ideal comparison with the few other outbursts known for similar systems. Aims. We extend our previous analysis of the Mira and the expanding shock from the explosion to detail the time development of the photoionized Mira wind, circumstellar medium, and shocked circumstellar environment to derive their physical parameters and how they relate to large scale structure of the environment, extending the previous coverage to more than 500 days after outburst. Methods. We use optical spectra obtained at high resolution with the Nordic Optical Telescope (NOT) (R ≈ 45 000 to 65 000) and medium resolution Ondřejov Observatory (R ≈ 12 000) data and compare the line variations with publicly available archival measurements at 30 GHz OVNR and at X-rays with Swift during the first four months of the outburst, through the end of the epoch of strong XR emission. We use nebular diagnostics and high resolution profile variations to derive the densities and locations of the extended emission. Results. We find that the higher the ionization and/or the higher the excitation energy, the more closely the profiles resemble the He II/Ca V-type high velocity shock profile discussed in Paper I. This also accounts for the comparative development If nitrogen is mainly N +3 or higher in the shock, the upper state of the [N II] nebular lines will contribute but if the oxygen is O +2 then this line is formed by recombination, masking the nebular contributor, and the lower states are collisionally quenched but emit from the low density surroundings. Absorption lines of Fe-peak ions formed in the Mira wind were visible as P Cyg profiles at low velocity before Day 69, around the time of the X-ray peak and we identified many absorption transitions without accompanying emission for metal lines. The H Balmer lines showed strong P Cyg absorption troughs that weakened during the 2010 observing period, through Day 128. The Fe-peak line profiles and flux variations were different for permitted and forbidden transitions: the E1 transitions were not visible after Day 128 but had shown a narrow peak superimposed on an extended (200 km s −1 ) blue wing, while the M1 and E2 transitions persisted to Day 529, the last observation, and showed extended redshifted wings up of the same velocity. We distinguish the components from the shock, the photoionized environment, and the chromosphere and inner Mira wind using spectra taken more than one year after outburst. The multiple shells and radiative excitation phenomenology are similar to those recently cited for GRBs and SNIa.

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“…Martin et al 1994) but extremely rare in the symbiotic giants. In fact, the Li enhancement is thus far detected only in the symbiotic Mira V407 Cyg, where it can probably be explained as a consequence of hot bottom burning, which occurs in stars with initial masses in the range 4-6 M (Tatarnikova et al 2003). Such an explanation is, however, unlikely in the case of low mass, < ∼ 1 M , nonpulsating giants in RS Oph and T CrB.…”

Section: Presence Of the LI I λ6707 Absorption Linementioning

confidence: 98%

Spectroscopic orbits and variations of RS Ophiuchi

Brandi

Quiroga

Mikołajewska³

et al. 2009

A&A

111

138

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Aims. The aims of our study are to improve the orbital elements of the giant and to derive the spectroscopic orbit for the white dwarf companion of the symbiotic system RS Oph. Spectral variations related to the 2006 outburst are also studied. Methods. We performed an analysis of about seventy optical and near infrared spectra of RS Oph that were acquired between 1998 and June 2008. The spectroscopic orbits were obtained by measuring the radial velocities of the cool component absorption lines and the broad Hα emission wings, which seem to be associated with the hot component. A set of cF-type absorption lines were also analyzed for a possible connection with the hot component motion. We also confirm the presence of the Li I doublet in RS Oph and its radial velocities fit very well to the M-giant radial velocity curve. Regardless of the mechanism involved to produce lithium, its origin is most likely from within the cool giant rather than material captured by the giant at the time of the nova explosion. The quiescent spectra reveal a correlation of the H I and He I emission line fluxes with the monochromatic magnitudes at 4800 Å, indicating that the hot component activity is responsible for those flux variations. We also discuss the spectral characteristics around 54-55 and 240 days after the 2006 outburst. In April 2006 most of the emission lines present a broad pedestal with a strong and narrow component at about −20 km s −1 and two other extended emission components at −200 and +150 km s −1 . These components could originate in a bipolar gas outflow supporting the model of a bipolar shock-heated shell expanding through the cool component wind perpendicularly to the binary orbital plane. Our observations also indicate that the cF absorption system was disrupted during the outburst, and restored about 240 days after the outburst, which is consistent with the resumption of accretion.

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Lithium in the symbiotic Mira V407 Cyg

Cited by 21 publications

References 26 publications

The spectroscopic evolution of the symbiotic-like recurrent nova V407 Cygni during its 2010 outburst

The spectroscopic evolution of the symbiotic-like recurrent nova V407 Cygni during its 2010 outburst

The spectroscopic evolution of the symbiotic-like recurrent nova V407 Cygni during its 2010 outburst

Spectroscopic orbits and variations of RS Ophiuchi

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