Register for updates

 
 

Astronomy & Astrophysics
RSS Feed
Astronomers Discover Giant Relic of Disrupted "Tadpole" Galaxy
Monday, November 19, 2018 9:00:00 AM

Discovery illuminates how and why galaxies disappear, say TAU researchers

A team of astronomers from Israel, the United States and Russia have identified a disrupted galaxy resembling a giant tadpole, complete with an elliptical head and a long, straight tail, about 300 million light years away from Earth. The galaxy is 1 million light-years long from end to end, 10 times longer than the Milky Way.

"We have found a giant, exceptional relic of a disrupted galaxy," says Dr. Noah Brosch of The Florence and George Wise Observatory at Tel Aviv University's School of Physics and Astronomy, who led the research for the study.

When galaxies are disrupted and disappear, their stars are either incorporated into more massive galaxies or are ejected into intergalactic space. "What makes this object extraordinary is that the tail alone is almost 500,000 light-years long," says Prof. R. Michael Rich of UCLA. "If it were at the distance of the Andromeda galaxy, which is about 2.5 million light-years from Earth, it would reach a fifth of the way to our own Milky Way."

Drs. Brosch and Rich collaborated on the study with Dr. Alexandr Mosenkov of St. Petersburg University and Dr. Shuki Koriski of TAU's Florence and George Wise Observatory and School of Physics and Astronomy. The results were published in the Monthly Notices of the Royal Astronomical Society.

According to the study, the giant "tadpole" was produced by the disruption of a small, previously invisible dwarf galaxy containing mostly stars. When the gravitational force of two visible galaxies pulled on stars in this vulnerable galaxy, the stars closer to the pair formed the "head" of the tadpole. Stars lingering in the victim galaxy formed the "tail."

"The extragalactic tadpole contains a system of two very close 'normal' disk galaxies, each about 40,000 light-years across," says Dr. Brosch. "Together with other nearby galaxies, the galaxies form a compact group." The galaxy is part of a small group of galaxies called HCG098 that will merge into a single galaxy in the next billion years.

Such compact galaxy groups were identified in 1982 by astronomer Paul Hickson, who published a catalog of 100 such groups. The Hickson Compact Groups examine environments with high galaxy densities that are not at the core of a "cluster" of galaxies (clusters contain thousands of galaxies themselves). The "tadpole galaxy" is listed as No. 98 in the Hickson Compact Group catalog.

"In compact group environments, we believe we can study 'clean' examples of galaxy-galaxy interactions, learn how matter is transferred between the members, and how newly accreted matter can modify and influence galaxy growth and development," says Dr. Brosch.

For the research, the scientists collected dozens of images of the targets, each exposed through a wide filter that selects red light while virtually eliminating extraneous light pollution. "We used a relatively small, 70-cm telescope at the Wise Observatory and an identical telescope in UCLA, both of which were equipped with state-of-the-art CCD cameras," says Dr. Brosch. The two telescopes are collaborating on a project called the Halos and Environments of Nearby Galaxies Survey.

The new study is part of a long-term project at TAU's Florence and George Wise Observatory, which explores the skies at low light levels to detect the faintest details of studied galaxies.




Latest News

Breast Cancer Recruits Bone Marrow Cells to Increase Cancer Cell Proliferation

Cancer-associated fibroblasts are derived from bone marrow cells called mesenchymal stromal cells, TAU researchers say.

Epigenetic Map May Pave Way for New Therapeutic Solutions to Hearing Loss

Understanding the expression of and controlling the genes involved in hearing are milestone discoveries, TAU researchers say.

Gas Clouds Whirling Around Black Hole Form Heart of Extremely Distant Luminous Astronomical Object

Discovery is the first detailed observation of the environs of a massive black hole outside the Milky Way.

The Tactics Behind "Taking to the Streets"

A new book by TAU researcher explores importance of public space in the design of social protests.

Training Program for Adults with Intellectual Disabilities Opens at TAU's School of Dental Medicine

Pilot program launched by TAU and AKIM helps students find jobs and changes attitudes about people with special needs.

TAU and its American Friends to Honor Susan and Henry Samueli at International Gala in Los Angeles

Philanthropists and Stanley Cup Winners to be recognized; Noa Tishby to serve as event emcee.

Astronomers Discover Giant Relic of Disrupted "Tadpole" Galaxy

Discovery illuminates how and why galaxies disappear, say TAU researchers.

Drug Candidate May Recover Vocal Abilities Lost to ADNP Syndrome

Protein snippet normalizes disrupted neural connectivity caused by genetic disorder, TAU researchers say.

TAU and Northwestern University Launch Joint Nanoscience Program

Collaboration to include student exchange program, post-doctoral scholarships and research grants.

Scientists Use Patients' Own Cells and Materials to Engineer Fully Personalized Tissue Implants of Any Kind

Risk of an immune response to an organ implant virtually disappears, TAU researchers say.

contentSecondary
c

© 2018 American Friends of Tel Aviv University
39 Broadway, Suite 1510 | New York, NY 10006 | 212.742.9070 | info@aftau.org
Privacy policy | Tel Aviv University