. | . |
Galaxy outskirts likely hunting grounds for dying massive stars and black holes by Staff Writers Rochester NY (SPX) Jul 30, 2018
Findings from a Rochester Institute of Technology study provide further evidence that the outskirts of spiral galaxies host massive black holes. These overlooked regions are new places to observe gravitational waves created when the massive bodies collide, the authors report. The study winds back time on massive black holes by analyzing their visible precursors - supernovae with collapsing cores. The slow decay of these massive stars creates bright signatures in the electromagnetic spectrum before stellar evolution ends in black holes. Using data from the Lick Observatory Supernova Search, a survey of nearby galaxies, the team compared the supernovae rate in outer spiral galaxies with that of known hosts - dwarf/satellite galaxies - and found comparable numbers for typical spiral outskirts and typical dwarf galaxies, roughly two core-collapse supernovae per millennium. The study, "Supernova Rate beyond the Optical Radius," will appear in an upcoming issue of Astrophysical Journal Letters. Low levels of elements heavier than hydrogen and helium found in dwarf/satellite galaxies create favorable conditions for massive black holes to form and create binary pairs. A similar galactic environment in the outer disks of spiral galaxies also creates likely hunting grounds for massive black holes, said Sukanya Chakrabarti, lead author and assistant professor in the RIT School of Physics and Astronomy. "If these core-collapse supernovae are the predecessors to the binary black holes detected by LIGO (Laser Interferometer Gravitational-wave Observatory), then what we've found is a reliable method of identifying the host galaxies of LIGO sources," said Chakrabarti. "Because these black holes have an electromagnetic counterpart at an earlier stage in their life, we can pinpoint their location in the sky and watch for massive black holes." The study's findings complement Chakrabarti's 2017 study, which showed that the outer parts of spiral galaxies could contribute to LIGO detection rates. The regions form stars at a comparable rate to dwarf galaxies and are low in heavy element content, creating a conducive home for massive black holes. The current study isolates potential candidates within these favorable galactic environments. "We see now that these are both important contributors," Chakrabarti said. "The next step is to do deeper surveys to see if we can improve the rate." Co-author Brennan Dell, a recent graduate from RIT's computer science program, analyzed the data with Chakrabarti during his undergraduate co-op. "This work may help us determine which galaxies to be on the lookout for electromagnetic counterparts of massive black holes," Dell said.
NASA's Fermi Traces Source of Cosmic Neutrino to Monster Black Hole Greenbelt MD (SPX) Jul 13, 2018 For the first time ever, scientists using NASA's Fermi Gamma-ray Space Telescope have found the source of a high-energy neutrino from outside our galaxy. This neutrino traveled 3.7 billion years at almost the speed of light before being detected on Earth. This is farther than any other neutrino whose origin scientists can identify. High-energy neutrinos are hard-to-catch particles that scientists think are created by the most powerful events in the cosmos, such as galaxy mergers and material falli ... read more
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |