arXiv subjects

Michael W. Healy-Kalesh

Publications and source records attributed to Michael W. Healy-Kalesh.

3 recordsLinked to original sources

arXiv2026

Infrared Cavity Surrounding T Pyxidis: Evidence of a Nova Super-remnant?

Nova super-remnants (NSR) are shell-like structures spanning tens of parsecs that are predicted to grow around all recurrent novae as a result of repeated ejecta sweeping up the surrounding material. After the first NSR was discovered in the Andromeda Galaxy around M31N 2008-12a, a number of Galactic NSRs have been uncovered, as has the first NSR in the Large Magellanic Cloud. Here we report an apparent infrared cavity surrounding the Galactic recurrent nova, T Pyxidis, which we suggest may be a nova super-remnant and discuss the implications.

astro-ph.HE↗

arXiv2025

Discovery of a nova super-remnant surrounding the recurrent nova LMCN 1971-08a in the Large Magellanic Cloud

A nova super-remnant (NSR) is a greatly-extended structure grown by repeated nova eruptions sweeping the surrounding material away from a nova into a dense outer shell and are predicted to form around all novae. To date, four NSRs are known, with three located in the Galaxy and one residing in M31. Here we present the discovery of the first NSR in the Large Magellanic Cloud and only the second extragalactic nova shell to be identified, hosted by the recurrent nova LMCN 1971-08a. The structure is coincident with the nova, has a circular morphology and is visible in narrowband H$α$ and [S II] filters but very faint in [O III], as expected. HI data also potentially reveal the existence of a coincident structure. Further, with a diameter of ${\sim}200$ pc, this NSR is the largest example yet found, with models indicating an ${\sim}4130 \ \text{M}_{\odot}$ shell expanding at ${\sim}20 \ \text{km} \ \text{s}^{-1}$ into the surrounding medium and an age of $\sim$2.4 Myr. The existence of the NSR also suggests that LMCN 1971-08a may have a much shorter recurrence period than currently presumed.

astro-ph.GA↗

arXiv2023

AT 2023prq: A Classical Nova in the Halo of the Andromeda Galaxy

The classical nova, AT 2023prq, was discovered on 2023 August 15 and is located at a distance of 46 kpc from the Andromeda Galaxy (M 31). Here we report photometry and spectroscopy of the nova. The 'very fast' ($t_{2,r^{\prime}}\sim3.4$ d) and low luminosity ($M_{r^{\prime}}\sim-7.6$) nature of the transient along with the helium in its spectra would indicate that AT 2023prq is a 'faint-and-fast' He/N nova. Additionally, at such a large distance from the centre of M 31, AT 2023prq is a member of the halo nova population.

astro-ph.HE↗