NGC 1386

Lore & Background

NGC 1386 was discovered by Johann Friedrich Julius Schmidt on January 19, 1865, while he was director of the National Observatory of Athens, inspecting Cape catalogue nebulae with a 6 ft refractor. Along with it, he discovered NGC 1381, NGC 1382, NGC 1389, and NGC 1428; the discoveries were published in 1876 in the work 'Über einige im Cape-Catalog fehlende Nebel'. The galaxy is seen nearly edge-on and features a spiral pattern with dust lanes; no HII regions are visible in Carnegie Atlas images, though HII emission has been detected in the arms. Two ring structures are present, with diameters of 0.5 and 1.67 arcminutes. The central region has three distinct kinematic components: low-velocity-dispersion gas rotating in the disk, a bipolar outflow within the inner 150 pc with an outflow rate of 0.1 solar masses per year, and a possible inward-streaming component along the spiral. Observations by the Very Large Array at 8.4 GHz reveal a linear radio feature extending south of the nucleus, with a marginally detectable north extension. A similar linear feature has been observed by the Hubble Space Telescope in [O III] and [N II] + Hα. An emission plume extends one arcsecond east-northeast of the nucleus. No polycyclic aromatic hydrocarbon emission has been detected in mid-infrared observations of the central 20 pc, but mild silicate absorption is present, possibly from a dust torus.

Reader's Guide

NGC 1386 is significant as one of the nearest type 2 Seyfert galaxies, providing a valuable laboratory for studying active galactic nuclei and their interaction with the host galaxy. Its active nucleus is obscured by a Compton-thick column with high column density, as measured by NuSTAR, implying that a torus covers much of the nucleus and obscures soft X-rays while harder X-rays, indicated by the Fe-Kα line, are observed. The galaxy hosts a cosmic water maser and features a circumnuclear HII region; the border between the narrow-line region photoionized by the AGN and surrounding HII regions is estimated at 6 arcseconds (310 parsecs) from the nucleus. A faint inclined ring of emission extending up to 12 arcseconds in [N II] + Hα indicates additional HII regions. The galaxy's redshift is smaller than that of the Fornax Cluster, leading to the assumption it is a foreground galaxy; Makarov and Karachentsev grouped it in the NGC 1386 group along with NGC 1389 and NGC 1396. Its legacy lies in its role as a nearby example of a Seyfert galaxy with a well-studied, obscured nucleus and outflow structures.

Did You Know?

• NGC 1386 is the only Seyfert galaxy in the Fornax Cluster.
• Its black hole mass is estimated from stellar velocity dispersion.
• Observations by NuSTAR measured a Compton-thick column with high column density obscuring the nucleus.