Showing posts with label N44. Show all posts
Showing posts with label N44. Show all posts

Saturday, November 06, 2021

Mysterious “Superbubble” Hollows Out Nebula in New Hubble Image

N44
Image credit: NASA, ESA, V. Ksoll and D. Gouliermis (Universität Heidelberg), et al.;
Processing: Gladys Kober (NASA/Catholic University of America)


N44 is a complex nebula filled with glowing hydrogen gas, dark lanes of dust, massive stars, and many populations of stars of different ages. One of its most distinctive features, however, is the dark, starry gap called a “superbubble,” visible in this Hubble Space Telescope image in the upper central region.

The hole is about 250 light-years wide and its presence is still something of a mystery. Stellar winds expelled by massive stars in the bubble's interior may have driven away the gas, but this is inconsistent with measured wind velocities in the bubble. Another possibility, since the nebula is filled with massive stars that would expire in titanic explosions, is that the expanding shells of old supernovae sculpted the cosmic cavern..

Astronomers have found one supernova remnant in the vicinity of the superbubble and identified an approximately 5 million year difference in age between stars within and at the rim of the superbubble, indicating multiple, chain-reaction star-forming events. The deep blue area at about 5 o’clock around the superbubble is one of the hottest regions of the nebula and the area of the most intense star formation..

N44 is an emission nebula, which means its gas has been energized, or ionized, by the radiation of nearby stars. As the ionized gas begins to cool from its higher-energy state to a lower-energy state, it emits energy in the form of light, causing the nebula to glow. Located in the Large Magellanic Cloud, N44 spans about 1,000 light-years and is about 170,000 light-years away from Earth..


Media Contact:

Claire Andreoli
NASA's
Goddard Space Flight Center
301-286-1940

Editor: Andrea Gianopoulos

Source: NASA/Hubble



Friday, August 31, 2012

NGC 1929 in N44: A Surprisingly Bright Superbubble

Credit X-ray: NASA/CXC/U.Mich./S.Oey,

This composite image shows a superbubble in the Large Magellanic Cloud (LMC), a small satellite galaxy of the Milky Way, located about 160,000 light years from Earth. Many new stars, some of them very massive, are forming in the star cluster NGC 1929, which is embedded in the nebula N44. The massive stars produce intense radiation, expel matter at high speeds, and race through their evolution to explode as supernovas. The winds and supernova shock waves carve out huge cavities called superbubbles in the surrounding gas. X-rays from NASA's Chandra X-ray Observatory (blue) show hot regions created by these winds and shocks, while infrared data from NASA's Spitzer Space Telescope (red) outline where the dust and cooler gas are found. The optical light from the 2.2m Max-Planck-ESO telescope (yellow) in Chile shows where ultraviolet radiation from hot, young stars is causing gas in the nebula to glow.

A long-running problem in high-energy astrophysics has been that some superbubbles in the LMC, including N44, give off a lot more X-rays than expected from models of their structure. A Chandra study published in 2011 showed that there are two extra sources of the bright X-ray emission: supernova shock waves striking the walls of the cavities, and hot material evaporating from the cavity walls. The observations show no evidence for an enhancement of elements heavier than hydrogen and helium in the cavities, thus ruling out this possibility as an explanation for the bright X-ray emission. This is the first time that the data have been good enough to distinguish between different sources of the X-rays produced by superbubbles.

The Chandra study of N44 and another superbubble in the LMC was led by Anne Jaskot from the University of Michigan in Ann Arbor. The co-authors were Dave Strickland from Johns Hopkins University in Baltimore, MD, Sally Oey from University of Michigan, You-Hua Chu from University of Illinois and Guillermo Garcia-Segura from Instituto de Astronomia-UNAM in Ensenada, Mexico.

NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

Fast Facts for NGC 1929:

Release Date: August 30, 2012
Scale: Image is 25 arcmin across (1200 light years)
Category:
Normal Stars & Star Clusters
Coordinates: (J2000) RA 05h 22m 17.00s | Dec -67° 76' 38.00"
Constellation:
Dorado
Observation Date: Sept 22, 2002
Observation Time: 5 hours 33 min.
Obs. ID: 3356
Instrument:
ACIS
References: Jaskot, A.E. et al 2011, ApJ, 729, 28; arXiv:1101.0280