A 500 kpc HI Tail of the Virgo Pair NGC4532/DDO137 Detected by ALFALFA

TL;DR

This paper reports the discovery of a 500 kpc HI tail in the Virgo Cluster pair NGC 4532/DDO 137, detected by the ALFALFA survey, indicating galaxy harassment effects with no optical counterparts.

Contribution

First detection of a massive, extended HI tail in the Virgo Cluster pair NGC 4532/DDO 137 using ALFALFA data, highlighting galaxy harassment processes.

Findings

HI tail extends ~500 kpc with 7 x 10^8 solar masses

No optical counterparts detected at 26.5 mag/arcsec^2

Tail likely caused by galaxy harassment

Abstract

HI observations of the Virgo Cluster pair NGC 4532/DDO 137, conducted as part of the Arecibo Legacy Fast ALFA Survey (ALFALFA), reveal an HI feature extending ~500 kpc to the southwest. The structure has a total mass of up to 7 x 10^8 solar masses, equivalent to 10% of the pair HI mass. Optical R imaging reveals no counterparts to a level of 26.5 magnitudes per square arcsec. The structure is likely the result of galaxy harassment.