Rise and fall of the dust shell of the classical nova V339 Delphini

Abstract

We present infrared spectroscopy of the classical nova V339 Del, obtained over an ∼2-yr period. The infrared emission lines were initially symmetrical, with half width half-maximum velocities of 525 km s −1 . In later (t 77 d, where t is the time from outburst) spectra, however, the lines displayed a distinct asymmetry, with a much stronger blue wing, possibly due to obscuration of the receding component by dust. Dust formation commenced at approximately day 34.75 at a condensation temperature of 1480 ± 20 K, consistent with graphitic carbon. Thereafter, the dust temperature declined with time as T d ∝ t −0.346 , also consistent with graphitic carbon. The mass of dust initially rose, as a result of an increase in grain size and/or number, peaked at approximately day 100, and then declined precipitously. This decline was most likely caused by grain shattering due to electrostatic stress after the dust was exposed to X-radiation. The appendix summarizes Planck means for carbon and the determination of grain mass and radius for a carbon dust shell.

Asymmetric Velocity Distributions from Halo Density Profiles in the Eddington Approach

“…The asymmetry is negative, opposite to what is commonly believed, see e.g. Drukier et al (1986); Collar & et al (1992); Vergados (2000); Evans et al (2000), Hansen et al (2006) 2. The choice β ∞ = 1, β 0 = 0.…”

“…220 km/s. Extensions of this M-B distribution were also considered, in particular those that were axially symmetric with enhanced dispersion in the galactocentric direction Drukier et al (1986); Collar & et al (1992); Vergados (2000); Evans et al (2000). In all such distributions an upper cutoff υ esc = 2.84υ 0 was introduced by hand, in the range obtained by KochanekCochanek (1996).…”

Multiwavelength models SED of the classical nova V339 Del (Nova Del 2013) along its age

“…Using the near-IR photometry, [23] indicated first formation of the dust around one month after the optical maximum. Extensive studies of dust properties and its evolution were performed by [9] and [8] using the stratospheric observatory SOFIA and ground-based infrared observations. V339 Del was monitored by the Swift X-ray telescope with the first detection on September 19 (day 37) at harder energies of 1-10 keV, while the super-soft emission appeared later, on October 13, 2013 (day 61) [15].…”

“…A short review of V339 Del was presented by [12], [8] and [4]. In this contribution we present the SED in the optical to near-IR of the nova throughout its main stages of evolution: The fireball stage, transition to a harder spectrum, super-soft source phase and in the nebular phase.…”

Optical and Near-infrared High-resolution Spectroscopic Observations of Nova V2659 Cyg: Structure of Nova Ejecta and Origin of Two-distinct Velocity Systems

“…The grey spectrum in the bottom panel shows the relative flux of nearinfrared data scaled by 20 times. Line idenifications of the near-infrared spectrum was refered to[26,27,28,29].…”