NGC 1512 and NGC 1510
Wide-field view of NGC 1510 and NGC 1512 (ground-based view)
Videos
Zooming onto the galaxies NGC 1512 and NGC 1510
The gravitational dance between two
galaxies in our local neighbourhood has led to intriguing visual
features in both as witnessed in this new NASA/ESA Hubble Space
Telescope image. The tiny NGC 1510 and its colossal neighbour NGC 1512
are at the beginning of a lengthy merger, a crucial process in galaxy
evolution. Despite its diminutive size, NGC 1510 has had a significant
effect on NGC 1512’s structure and amount of star formation.
Galaxies come in a range of shapes and sizes, and astronomers use
this fact to classify them based on their appearance. NGC 1512, the
large galaxy to the left in this image, is classified as a barred spiral,
named after the bar composed of stars, gas and dust slicing through its
centre. The tiny NGC 1510 to the right, on the other hand, is a dwarf
galaxy. Despite their very different sizes, each galaxy affects the
other through gravity, causing slow changes in their appearances.
The bar in NGC 1512 acts as a cosmic funnel, channelling the raw materials required for star formation
from the outer ring into the heart of the galaxy. This pipeline of gas
and dust in NGC 1512 fuels intense star birth in the bright, blue,
shimmering inner disc known as a circumnuclear starburst ring, which
spans 2400 light-years.
Both the bar and the starburst ring are thought to be at least in
part the result of the cosmic scuffle between the two galaxies — a
merger that has been going on for 400 million years.
NGC 1512, which has been observed by Hubble in the past, is also home to a second, more serene, star-forming region in its outer ring. This ring is dotted with dozens of HII regions,
where large swathes of hydrogen gas are subject to intense radiation
from nearby, newly formed stars. This radiation causes the gas to glow
and creates the bright knots of light seen throughout the ring.
Remarkably, NGC 1512 extends even further than we can see in this
image — beyond the outer ring — displaying malformed, tendril-like
spiral arms enveloping NGC 1510. These huge arms are thought to be
warped by strong gravitational interactions with NGC 1510 and the
accretion of material from it. But these interactions are not just
affecting NGC 1512; they have also taken their toll on the smaller of
the pair.
The constant tidal tugging from its neighbour has swirled up the gas
and dust in NGC 1510 and kick-started star formation that is even more
intense than in NGC 1512. This causes the galaxy to glow with the blue
hue that is indicative of hot new stars.
NGC 1510 is not the only galaxy to have experienced the massive
gravitational tidal forces of NGC 1512. Observations made in 2015 showed
that the outer regions of the spiral arms of NGC 1512 were indeed once
part of a separate, older galaxy. This galaxy was ripped apart and
absorbed by NGC 1512, just as it is doing now to NGC 1510.
Together, the pair demonstrate how interactions between galaxies,
even if they are of very different sizes, can have a significant
influence on their structures, changing the dynamics of their
constituent gas and dust and even triggering starbursts. Such
interactions between galaxies, and galaxy mergers in particular, play a key role in galactic evolution.
Links
Contact
Mathias Jäger
ESA/Hubble, Public Information Officer
Garching, Germany
Tel: +49 176 62397500
Email: mjaeger@partner.eso.org
ESA/Hubble, Public Information Officer
Garching, Germany
Tel: +49 176 62397500
Email: mjaeger@partner.eso.org
