Copyright
NASA, ESA, D. Elmegreen (Vassar College), B.
Elmegreen (IBM’s Thomas J. Watson Research Center), J. Sánchez Almeida,
C. Munoz-Tunon & M. Filho (Instituto de Astrofísica de Canarias), J.
Mendez-Abreu (University of St Andrews), J. Gallagher (University of
Wisconsin-Madison), M. Rafelski (NASA Goddard Space Flight Center) &
D. Ceverino (Center for Astronomy at Heidelberg University). Hi-re image
In this NASA/ESA Hubble Space Telescope image, a firestorm of star birth is lighting up one end of the dwarf galaxy Kiso 5639.
Kiso
5639 is shaped like a pancake but, because it is tilted edge-on, it
resembles a skyrocket, with a brilliant blazing head and a long,
star-studded tail. Its appearance earns it a place in the “tadpole”
class of galaxies.
The bright pink head is from the glow of
hydrogen, lit up by the burst of new stars. The mass of these young
stars equals about a million Suns. The stars are grouped into large
clusters that formed less than a million years ago.
Stars consist
mainly of hydrogen and helium, but cook up heavier elements such as
oxygen and carbon. When the stars die, they release their heavy elements
and enrich the surrounding gas. In Kiso 5639, the bright gas in the
galaxy’s head is more deficient in heavy elements than the rest of the
galaxy. Astronomers think that the latest star-formation event was
triggered when the galaxy accreted primordial gas from its surroundings,
since intergalactic space contains more pristine, hydrogen-rich gas.
Cavities
in the gas are due to numerous supernova detonations – like bursts of
fireworks in the sky – carving out holes of superheated gas.
The
elongated tail, seen stretching away from the galaxy’s head and
scattered with bright blue stars, contains at least four distinct
star-forming regions. These stars appear to be older than those in the
star-forming head.
Wispy filaments, comprising gas and some stars, extend from the main body of the cosmic tadpole.
The
observations were taken in February 2015 and July 2015 with Hubble's
Wide Field Camera 3. Kiso 5639 is 82 million light-years from us and its
head is some 2700 light-years across.
Source: ESA/Space Images
