An anomalous concentration of QSOs around NGC 3079

TL;DR

The paper reports a significant excess of quasars near galaxy NGC 3079, suggesting a possible physical association rather than a chance alignment, with implications for understanding quasar distribution.

Contribution

It presents evidence of an anomalous concentration of QSOs around NGC 3079, challenging the assumption of random quasar distribution and exploring potential physical connections.

Findings

At least 21 QSOs within 1 degree of NGC 3079

Surface density near the galaxy is about 100 times the average

Probability of chance alignment is less than one in a million

Abstract

It is shown that there are at least 21 QSOs within 1 degree of the nearby active spiral galaxy NGC3079. Many of them are bright (mag<18) so that the surface density of those closer than 15 arc minutes to the galaxy centre is close to 100 times the average in the field. The probability that this is an accidental configuration is shown to be less or equal to one in a million. Discovery selection effects and microlensing fail by a large factor to explain the phenomenon, suggesting that the QSOs may lie in the same physical space as NGC3079. However, two of them make up the apparently lensed pair 0957+561A, B whose lensing galaxy lies at z=0.355. This problem is discussed in the concluding section.