Tag Archives: black hole

J1502+1115: A Triple Black Hole Galaxy 

innerBhs_vlbi_619
Image Credit: R. P. Deane (U. Capetown) et al.

 Most galaxies contain one supermassive black hole – why does this galaxy have three? The likely reason is that galaxy J1502+1115 is the product of the recent coalescence of three smaller galaxies. The two closest black holes are shown above resolved in radio waves by large coordinated array of antennas spread out over Europe, Asia, and Africa. These two supermassive black holes imaged are separated by about 500 light years and each has a likely mass about 100 million times the mass of our Sun. Currently, J1502+1115, at a redshift of 0.39, is one of only a few triple black hole system known and is being studied to learn more about galaxy and supermassive black hole interaction rates during the middle ages of our universe. Gravitational radiation emitted by such massive black hole systems may be detectable by future observatories.

APOD NASA 07-Jul-14

Spiral galaxy NGC 1097

c4ab3333271e1c29779cebb6d8be6161.1824x0_q100_watermark_watermark_opacity-10_watermark_position-4_watermark_text-Copyright Rick Stevenson, 2013

NGC 1097 is a barred spiral galaxy about 45 million light-years away in the constellation Fornax. It was discovered by William Herschel on 9 October 1790. Three supernovae (SN 1992bd, SN 1999eu, and SN 2003B) have been observed in NGC 1097.

NGC 1097 is also a Seyfert galaxy. Deep photographs revealed four narrow optical jets that appear to emanate from the nucleus. These have been interpreted as manifestations of the (currently weak) active nucleus. Subsequent analysis of the brightest jet’s radio-to-X-ray spectral energy distribution were able to rule out synchrotron and thermal free-free emission. The optical jets are in fact composed of stars. The failure to detect atomic hydrogen gas in the jets (under the assumption that they were an example of tidal tails) using deep 21 cm HI imaging with the Very Large Array radio telescope and numerical simulations led to the current interpretation that the jets are actually the shattered remains of a cannibalized dwarf galaxy.

Like most massive galaxies, NGC 1097 has a supermassive black hole at its center. Around the central black hole is a ring ofstar-forming regions with a network of gas and dust that spirals from the ring to the black hole.

NGC 1097 has two satellite galaxies. Dwarf elliptical galaxy NGC 1097A is the larger of the two. It is a peculiar elliptical galaxy that orbits 42,000 light-years from the center of NGC 1097. Dwarf galaxy NGC 1097B (5 x 106 solar masses), the outermost one, was discovered by its HI emission, and appears to be a typical dwarf irregular. Little else is known about it.

Imaging telescopes or lenses: Ceravolo 300 Astrograph (f/9)
Imaging cameras: Apogee Alta U16M
Mounts: Astro-Physics AP900
Guiding telescopes or lenses: Ceravolo 300 Astrograph (f/9)
Guiding cameras: Starlight Xpress Lodestar
Software: DC-3 Dreams ACP, Pleaides Astrophoto PixInsight 1.8, Maxim DL
Filters: Astrodon E-series 2 LRGB
Accessories: FLI Atlas focuser
Dates: Nov. 4, 2013
Frames: 88×900″
Integration: 22.0 hours

Author: Rick Stevenson
AstroPhotography of the day by SPONLI 28 May 2014

The View Near a Black Hole

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Illustration Credit: April Hobart, CXC

In the center of a swirling whirlpool of hot gas is likely a beast that has never been seen directly: a black hole. Studies of the bright light emitted by the swirling gas frequently indicate not only that a black hole is present, but also likely attributes. The gas surrounding GRO J1655-40, for example, has been found to display an unusual flickering at a rate of 450 times a second. Given a previous mass estimate for the central object of seven times the mass of our Sun, the rate of the fast flickering can be explained by a black hole that is rotating very rapidly. What physical mechanisms actually cause the flickering — and a slower quasi-periodic oscillation(QPO) – in accretion disks surrounding black holes and neutron stars remains a topic of much research.

NASA APOD 23-Mar-2014

NGC 4395 in Canes Venatici

NGC4395
NGC 4395
 is a low surface brightness spiral galaxy with a halo that is about 8′ in diameter. It has several wide areas of greater brightness running northwest to southeast. The one furthest southeast is the brightest. Three of the patches have their own NGC numbers: 4401, 4400, and 4399 running east to west.

The nucleus of NGC 4395 is active and the galaxy is classified as a Seyfert. It is notable for containing one of the smallest supermassive black hole with an accurately-determined mass. The central black hole has a mass of “only” 300,000 sun masses, which would make it a so-called “intermediate-mass black hole”.

Mount: NEQ6 Pro SynScan
Equipment: Skywatcher Black Diamond ED120 APO
Type of camera: Moravian G2 8300
Exposure time: Moravian G2 LRGB 620:210:150:300
Total: 21h 20 min.
Focal Length: 765 mm with Skywatcher
+ 0,85 Reducer
Distance 4.83 Mpc
Data reduction with PixInsight 1.7, Photoshop

Autor: Dieter Beer

AstroPhotography of the day by SPONLI
31 December 2013

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