The frequency distribution of the height above the Galactic plane for the novae

TL;DR

This study analyzes the vertical distribution of 64 novae to test the hypothesis of two distinct populations, 'disk' and 'bulge', based on their height above the Galactic plane, finding significant differences supporting this distinction.

Contribution

It provides empirical evidence for two separate nova populations in the Galaxy by analyzing their height distribution and applying statistical tests.

Findings

Fast novae are found at greater heights, up to 3700 pc.

Slow novae are more concentrated near the Galactic plane, within 1700 pc.

Statistical analysis supports the existence of two distinct nova populations.

Abstract

In order to examine the hypothesis of the existence of two different kinds of nova populations in the Galaxy - 'disk' novae and 'bulge' novae - the frequency distribution in the z-direction was obtained for 64 novae. The fact that large number of fast novae related to disk novae are found at a significant distance from the Galactic plane (up to z~3700 pc) can't result from photometric measurements errors. Slow novae considered to belong to bulge novae show more close concentration to the Galactic plane (z<1700 pc). A Kolmogorov-Smirnov test run on the data showed that the two populations hypothesis probability amounts to 95.56%.