Astronomers measure mass of smallest black hole

[star_sirius]

<i> Astronomers measure mass of smallest black hole<br />OHIO STATE UNIVERSITY NEWS RELEASE<br />Posted: February 22, 2005<br /><br />A group led by astronomers from The Ohio State University and the Technion-Israel Institute of Technology have measured the mass of a unique black hole, and determined that it is the smallest found so far. <br /><br />Early results indicate that the black hole weighs in at less than a million times the mass of our sun -- which would make it as much as 100 times smaller than others of its type. <br /><br />To get their measurement, astronomers used NASA's Hubble Space Telescope and a technique similar to Doppler radar -- the method that meteorologists use to track weather systems. <br /><br />The black hole lies 14 million light-years away, in the center of the galaxy NGC 4395. One light-year is the distance light travels in one year -- approximately six trillion miles. <br /><br />Astronomers consider NGC 4395 to be an "active galaxy," one with a very bright center, or nucleus. Current theory holds that black holes may literally be consuming active galactic nuclei (AGNs). Black holes in AGNs are supposed to be very massive. <br /><br />NGC 4395 appears to be special, because the black hole in the center of the galaxy is much smaller than those found in other active galaxies, explained Ari Laor, professor of astronomy at the Technion, in Haifa, Israel, and Brad Peterson, professor of astronomy at Ohio State. <br /><br />While astronomers have found much evidence of black holes that are larger than a million solar masses or smaller than a few tens of solar masses, they haven't found as many midsize black holes -- ones on the scale of hundreds or thousands of solar masses. <br /><br />Black holes such as the one in NGC 4395 provide a step in closing that gap. <br /><br />Laor and Peterson and their colleagues used the Doppler radar-like technique to track the movement of gas around the center of NGC 4395. Whereas radar bounces a radio frequency signal off o</i> <div class="Discussion_UserSignature"> <font size="0" color="#10bdee"><strong>A dazzling bluish luminosity from A distant south pacific.</strong></font><p><br /><img id="cb51e87e-8221-424c-8ff2-78c95122196c" src="http://sitelife.livescience.com/ver1.0/Content/images/store/11/15/cb51e87e-8221-424c-8ff2-78c95122196c.Large.jpg" alt="blog post photo" /></p> </div>

 

[star_sirius]

Is NGC 4395 a type I or a type II Seyfert galaxy? Anybody? <div class="Discussion_UserSignature"> <font size="0" color="#10bdee"><strong>A dazzling bluish luminosity from A distant south pacific.</strong></font><p><br /><img id="cb51e87e-8221-424c-8ff2-78c95122196c" src="http://sitelife.livescience.com/ver1.0/Content/images/store/11/15/cb51e87e-8221-424c-8ff2-78c95122196c.Large.jpg" alt="blog post photo" /></p> </div>

 

[star_sirius]

It has small mass perhaps a type 1? <div class="Discussion_UserSignature"> <font size="0" color="#10bdee"><strong>A dazzling bluish luminosity from A distant south pacific.</strong></font><p><br /><img id="cb51e87e-8221-424c-8ff2-78c95122196c" src="http://sitelife.livescience.com/ver1.0/Content/images/store/11/15/cb51e87e-8221-424c-8ff2-78c95122196c.Large.jpg" alt="blog post photo" /></p> </div>

 

[Saiph]

it's the nearest seyfert I IIRC. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>