A new catalogue of Galactic novae: investigation of the MMRD relation and spatial distribution

Abstract

In this study, a new Galactic novae catalogue is introduced collecting important parameters of these sources such as their light curve parameters, classifications, full width half maximum (FWHM) of H α line, distances and interstellar reddening estimates. The catalogue is also published on a website with a search option via a SQL query and an online tool to re-calculate the distance/reddening of a nova from the derived reddening-distance relations. Using the novae in the catalogue, the existence of a maximum magnitude-rate of decline (MMRD) relation in the Galaxy is investigated. Although an MMRD relation was obtained, a significant scattering in the resulting MMRD distribution still exists. We suggest that the MMRD relation likely depends on other parameters in addition to the decline time, as FWHM H α , the light curve shapes. Using two different samples depending on the distances in the catalogue and from the derived MMRD relation, the spatial distributions of Galactic novae as a function of their spectral and speed classes were studied. The investigation on the Galactic model parameters implies that best estimates for the local outburst density are 3.6 and 4.2 ×10 −10 pc −3 yr −1 with a scale height of 148 and 175 pc, while the space density changes in the range of 0.4 − 16 × 10 −6 pc −3 . The local outburst density and scale height obtained in this study infer that the disk nova rate in the Galaxy is in the range of ∼ 20 to ∼ 100 yr −1 with an average estimate 67 +21 −17 yr −1 .

A Population of Heavily Reddened, Optically Missed Novae from Palomar Gattini-IR: Constraints on the Galactic Nova Rate

“…Previous estimates for the Galactic nova rate have primarily used the rate in the very local solar neighborhood to derive the local outburst rate density (although without a rigorous quantification of the completeness), followed by extrapolation to the entire galaxy (e.g., Shafter 2017;Özdönmez et al 2018). Figure 10 summarizes our rate measurement in comparison to previous estimates.…”

“…The second class of techniques uses the statistics of a handful of bright and nearby Galactic novae to extrapolate the rate to the entire Galaxy, resulting in estimates in a large range of ≈30-300 yr −1 (Allen 1954;Sharov 1972;Liller & Mayer 1987;Hatano et al 1997;Shafter 1997Shafter , 2002Shafter , 2017Özdönmez et al 2018). However, all previous estimates are subject to the poorly quantified selection effects of the discovery of even the brightest optical novae (e.g., Schaefer 2014;Shafter 2017).…”

The distances to Novae as seen by Gaia

“…In all, we see the RDR as a new method that is applicable to most galactic novae, where its real error bars are comparable to the those of the much-vaunted expansion parallax. Ozdönmez et al (2018) puts together a catalog for essentially all galactic novae, listing distances and properties, all with good selections. A fraction of the novae are not able to have RDR distances, usually because the nova is past most of the Milky Way's dust so only a distance-limit is possible.…”

A Review of the Evolution of Classical Nova V2676 Oph: Formation of Molecules and Dust Grains

“…It is noted that there are two issues to be re-examined. First, the MMRD relation used in their study may be inaccucate as pointed out some studies [42,55,24]. In addition to the MMRD relation, the visual extinction determined by the "Balmer decrement" method (which requires the assumptions about recombination of hydrogen atoms and physical conditions) may be not sufficiently accurate.…”