NGC 2835

Lore & Background

NGC 2835 is located only 18.5 degrees from the galactic plane and is seen nearly face-on. The galaxy exhibits four or five spiral arms, which are visible in near infrared due to their population II stars. The spiral arms contain numerous HII regions and stellar associations, with the larger HII regions measuring about 5 arcseconds across. Although the galaxy is quite symmetric, the northern arms have HII regions that appear brighter than the southern ones, and the southern arms appear less developed in their outer parts than the northern arms.

The star formation rate in NGC 2835 is 1.3 solar masses per year, and its total stellar mass is 10^10 solar masses. At the center lies a supermassive black hole with an estimated mass of 3-10 million solar masses (10^6.72±0.3), determined from the spiral arm pitch angle.

NGC 2835 is the foremost galaxy in a small group called the NGC 2835 group (also known as LGG 172). Other identified members of this group include ESO 497-035 and ESO 565-001. At a projected separation of 2.2 degrees lies NGC 2784 and its own small galaxy group.

Reader's Guide

NGC 2835 holds significance as a nearby, nearly face-on intermediate spiral galaxy that provides a clear view of its spiral structure and star-forming regions. Its four or five spiral arms, traced in near infrared by population II stars, offer insights into the distribution of older stellar populations. The asymmetry in HII region brightness between the northern and southern arms, along with the less developed outer southern arms, suggests possible environmental influences or internal dynamics worth studying. The galaxy's star formation rate of 1.3 solar masses per year, combined with its total stellar mass of 10^10 solar masses, places it among low-mass spirals. The central supermassive black hole, with mass estimated from spiral arm pitch angle, adds to its value for studying black hole–galaxy scaling relations. As the leading member of the NGC 2835 group (LGG 172), it serves as a reference point for understanding small galaxy groups and their interactions. Its discovery by Wilhelm Tempel in 1884 adds historical context to the catalog of NGC objects.