Nearby active galaxy investigated with Chandra observatory

Utilizing NASA’s Chandra X-ray observatory, astronomers have carried out deep X-ray observations of a close-by lively galaxy referred to as NGC 5728 and its lively galactic nucleus (AGN). Outcomes of the observational marketing campaign, printed March 1 on the pre-print server arXiv, ship essential info concerning the properties of this AGN and the emission from it.

AGN are compact areas on the heart of a galaxy, extra luminous than the encircling galaxy gentle. They’re very energetic due both to the presence of a black hole or star formation exercise on the core of the galaxy.

Positioned some 146 million gentle years away within the constellation of Libra, NGC 5728 is an lively barred spiral galaxy with a measurement of practically 100,000 gentle years and an estimated mass of about 72 billion solar plenty. It’s a Seyfert galaxy of sort 1.9, with a closely obscured and complicated AGN powered by a supermassive black hole (SMBH) at its heart.

A staff of astronomers led by Anna Trindade Falcao of the Harvard-Smithsonian Heart for Astrophysics (CfA) in Cambridge, Massachusetts, determined to look at NGC 5728 with Chandra’s Superior CCD Imaging Spectrometer (ACIS) with the principle intention of figuring out the detailed morphological and spectral properties of the prolonged X-ray emission from the galaxy’s AGN.

“We analyze the deep Chandra statement of the CT AGN NGC 5728 to review the kpc-scale diffuse X-ray emission, each spectrally and spatially, as a perform of vitality,” the researchers wrote within the paper.

In end result, the observations detected a decrease vitality total extent of about 13,000 light years within the route of the foremost axis of NGC 5728, which can also be the route of the ionization bicone. The outcomes recommend an energy-related development within the measurement of the prolonged emission, with the softer emission (beneath 3 keV) being extra prolonged than the tougher emission.

The research discovered that the diffuse emission can also be prolonged within the cross-cone route and that the transmission within the cross-cone route is about 2% of the bicone route. The info point out the presence of arduous X-rays on kiloparsec scales, suggesting a non-uniform, clumpy torus construction, which permits the radiation to flee from the circumnuclear area to bigger radii.

Moreover, the outcomes present that the ratio of detected photons within the cross-cone to the bicone area is about 16%, beneath 3 keV, and reduces to roughly 5% for the three–6 keV vitality vary. The astronomers assume {that a} bigger focus of dense molecular clouds within the central area is perhaps the reason for this phenomenon since these clouds are chargeable for scattering and reflecting the high-energy photons from the nucleus within the galaxy disk.

By analyzing the information, the researchers concluded that thermal parts for NGC 5728 could be defined by interstellar medium interactions, shocks, or supernova remnants/star formation from the close by star-forming ring.

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