Search for broad absorption lines in spectra of stars in the field of supernova remnant RX J0852.0-4622 (Vela Jr.)

Abstract

Aims. Supernova remnant (SNR) RX J0852.0-4622 is one of the youngest and is most likely the closest among known Galactic SNRs. It was detected in X-rays, the 44 Ti γ-line, and radio. We obtain and analyze medium-resolution spectra of 14 stars in the direction towards the SNR RX J0852.0-4622 in an attempt to detect broad absorption lines of unshocked ejecta against background stars. Methods. Spectral synthesis is performed for all the stars in the wavelength range of 3740−4020 Å to extract the broad absorption lines of Ca II related to the SNR RX J0852.0-4622. Results. We do not detect any broad absorption line and place a 3σ upper limit on the relative depths of <0.04 for the broad Ca II absorption produced by the SNR. We detect narrow low and high velocity absorption components of Ca II. High velocity |V LSR | ∼ 100−140 km s −1 components are attributed to radiative shocks in clouds engulfed by the old Vela SNR. The upper limit to the absorption line strength combined with the width and flux of the 44 Ti γ-ray line 1.16 MeV lead us to conclude that SNR RX J0852.0-4622 was probably produced by an energetic SN Ic explosion.

Interstellar absorptions and shocked clouds towards the supernova remnant RX J0852.0-4622

“…Recently, we have performed a low‐ and high‐resolution spectroscopic survey of 14 stars in the field of RX J0852.0–4622, which is also known as Vela Jr. RX J0852.0–4622 is superimposed on the south‐east part of the Vela SNR. An analysis of low‐resolution observations in the region 3700–4000 Å was reported earlier (Iyudin et al ). Here, we address the high‐resolution spectral data, which cover a much broader spectral range.…”

“…The spectra of 14 stars in the direction of Vela Jr (for the positions of the stars, see Iyudin et al ) were obtained in 2008 March by the 3.6‐m European Southern Observatory (ESO) New Technology Telescope (NTT), equipped with the ESO multimode instrument (EMMI) spectrograph (echelle grating 14, cross‐dispersion grating 3, CCD mosaic 2076 × 4110). The full coverage is 3850–8620 Å with the gap at 5570–5650 Å; the central dispersion is 0.02 Å pix −1 and the resolving power is R = λ/Δλ = 88 600 (Δ v = 3.4 km s −1 ).…”

“…Its stellar flux is synthesized by applying the atlas9 code (Kurucz ) and synthvb (Tsymbal, Lyashko & Weiss ). A stellar atmosphere model of a standard star is calculated for the solar metallicity with parameters T eff = 16 200 K, log g = 3.56, V sin i = 24 km s −1 and IS absorption A v = 0.25 (Iyudin et al ).…”

Wavelength Calibration of the Hamilton Echelle Spectrograph

“…The effective temperature T ef f and gravity log g are found by the Balmer lines fit (cf. (Iyudin et al 2010)). The derived parameter values are T ef f =20000±1000 K and log g=3.…”

Magnetic field damping in the Vela Jr. SNR

“…Magnetic field damping in the Vela Jr. SNR Iurii Sushch Ti 44 gamma-ray line also suggests a core collapse origin with SNe types of Ic or Ibc (Iyudin et al, 2010). The density of the ambient medium is constrained by the lack of the X-ray thermal emission which places the upper limit at n 0 < 2.9 × 10 −2 D 1 kpc…”