John Mulchaey, director of the Observatories, serves as co-interim president of Carnegie as of January 1, 2018. He investigates groups and clusters of galaxies, elliptical galaxies, dark matter—the invisible material that makes up most of the universe—active galaxies and black holes. He is also a scientific editor for The Astrophysical Journal and is actively involved in public outreach and education.

Most galaxies including our own Milky Way, exist in collections known as groups, which are the most common galaxy systems and are important laboratories for studying galaxy formation and evolution. Mulchaey studies galaxy groups to understand the processes that affect most galaxies during their lifetimes.

As a graduate student, Mulchaey led the team that discovered that some groups are bright X-ray sources. The extent of the emission suggests that the X-rays originated in a very hot, low-density gas called the intragroup medium. X-ray observations of the medium have shown that the temperature is a scorching 10 million degrees. Temperatures this high should quickly disperse; but the intragroup medium does not. Astronomers believe that gravity is binding it. However, the mass required to confine the gas is much higher than the visible group mass. This suggests that galaxy groups are dominated by that elusive material called dark matter, which does not emit light but has a strong gravitational pull.

Although Mulchaey works extensively with space-based, X-ray telescopes, the optical telescopes at Carnegie’s Las Campanas Observatory play a central role in his research. X-ray images alone are not sufficient to uncover the nature of galaxy groups. Follow-up observations with large-aperture optical telescopes, such as Magellan, are necessary to determine galaxy type and distance.

The large Magellan telescopes have allowed Mulchaey to study distant galaxy groups for the first time. He is directly tracing how the group environment affects properties of individual galaxies. These observations suggest that galaxy-galaxy merging is very common in groups. For some groups, the galaxies may continue merging until they form a single massive galaxy. In the last few years, Mulchaey has uncovered several of these “fossil group” systems. Studies of them are proving to have important clues into the likely end state of most groups, including the Local Group, where our Milky Way resides.

Mulchaey received his B.S. in astrophysics from UC-Berkeley and his Ph. D. from the University of Maryland. He was a fellow at the Space Telescope Science Institute and at Carnegie before joining the  Carnegie staff. For more information see http://obs.carnegiescience.edu/users/mulchaey

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Kit Whitten in the plate analysis room. Photo by Cynthia Hunt
May 3, 2018

Cataloging Reflections by Kit Whitten, Carnegie Observatories Library Intern

It is commonly believed that when looking for valuable treasure, the best place to look is the attic—after all, works by Caravaggio, Van Gogh, Rembrandt, and Jackson Pollack have been discovered in attics—but not everyone thinks to look in the basement. Yet institutions like Carnegie Observatories often keep the best stuff in the basement.

The underground vault at the Observatories houses the nation’s second-largest, single-institution collection of astronomical glass plates, which are thin sheets of glass with an emulsion image of celestial bodies.  Photographic plates preceded plastic

April 27, 2018

Former Carnegie fellow and current trustee Sandy Faber has been selected to receive the 2018 American Philosophical Society’s Magellanic Premium Medal.  The medal is the nation’s oldest for scientific achievement. It was established in 1786. It is awarded from time to time “ to the author of the best discovery or most useful invention related to navigation, astronomy, or natural philosophy…”

Dr. Faber is the University of California, Santa Cruz, University Professor of Astronomy and Astrophysics and has been a Carnegie trustee since 1985.  After receiving a B.A. in physics from Swarthmore College, she pursued her Ph.D. in astronomy at Harvard, which she received in 1972. Much of

April 5, 2018

Pasadena, CA—Pomona College junior and returning Carnegie Observatories intern Sal Fu was awarded a Barry M. Goldwater Scholarship in recognition of her academic and research success and to support her continued “academic study and research in the fields of science, mathematics, and engineering.” Fu has participated in the Carnegie Summer Undergraduate Research program over the past two summers, working with staff astronomer Josh Simon studying dwarf galaxies and streams of stars surrounding our Milky Way using data from the Sloan Digital Sky Survey.

“The Summer Undergraduate Research Program at the Carnegie Observatories provides undergraduate students the exciting opportunity to

Carnegie Science, Carnegie Institution, Carnegie Institution for Science, Las Campanas Observatory
March 23, 2018

La Serena, Chile—Last week, scientists and staff from Carnegie’s Las Campanas Observatory volunteered for Astroday 2018 at a 170-year-old school in the nearby city of Las Serena, the Colegio Seminario Conciliar.

Organized by the Gemini Observatory, the daylong outreach event features activities including a planetarium, science projects, a 3-D movie, and night sky viewing. Several Chile-based astronomy facilities participated, both from the research and tourist sectors, all sharing the wonders of the universe with the community.

Since its inception in 2006, thousands of La Serena residents have participated in Astroday.

Led by Roberto Bermúdez, the Las Campanas

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The fund supports a postdoctoral fellowship in astronomy that rotates between the Carnegie Science departments of Terrestrial Magnetism in Washington, D.C., and the Observatories in Pasadena California. 

The Earthbound Planet Search Program has discovered hundreds of planets orbiting nearby stars using telescopes at Lick Observatory, Keck Observatory, the Anglo-Australian Observatory, Carnegie's Las Campanas Observatory, and the ESO Paranal Observatory.  Our multi-national team has been collecting data for 30 years, using the Precision Doppler technique.  Highlights of this program include the detection of five of the first six exoplanets, the first eccentric planet, the first multiple planet system, the first sub-Saturn mass planet, the first sub-Neptune mass planet, the first terrestrial mass planet, and the first transit planet.Over the course of 30 years we have improved the

The Giant Magellan Telescope will be one member of the next class of super giant earth-based telescopes that promises to revolutionize our view and understanding of the universe. It will be constructed in the Las Campanas Observatory in Chile. Commissioning of the telescope is scheduled to begin in 2021.

The GMT has a unique design that offers several advantages. It is a segmented mirror telescope that employs seven of today’s largest stiff monolith mirrors as segments. Six off-axis 8.4 meter or 27-foot segments surround a central on-axis segment, forming a single optical surface 24.5 meters, or 80 feet, in diameter with a total collecting area of 368 square meters. The GMT will

Along with Alycia Weinberger and Ian Thompson, Alan Boss has been running the Carnegie Astrometric Planet Search (CAPS) program, which searches for extrasolar planets by the astrometric method, where the planet's presence is detected indirectly through the wobble of the host star around the center of mass of the system. With over eight years of CAPSCam data, they are beginning to see likely true astrometric wobbles beginning to appear. The CAPSCam planet search effort is on the verge of yielding a harvest of astrometrically discovered planets, as well as accurate parallactic distances to many young stars and M dwarfs. For more see  http://instrumentation.obs.carnegiescience.edu/ccd/caps.

Staff member Nick Konidaris joined Carnegie in October 2017. He works on a variety of new optical instrumentation projects in astronomy. He  recently began working on a new development platform for the 40-inch Swope telescope at Carnegie's Las Campanas Observatory. It is called the Rapid Response Swope Spectrograph and Imager (R2S2I). When operational, it will be a workhorse instrument and development platform.

Prior to Carnegie, he was director of product management at Kairos Aerospace in Mountain View, CA. Konidaris received a B.S. in physics from Carnegie Mellon University, and conducted coursework in electrical engineering before obtaining a Ph.D. in astrophysics from the

Experimental petrologist Michael Walter became director of the Geophysical Laboratory beginning April 1, 2018. His recent research has focused on the period early in Earth’s history, shortly after the planet accreted from the cloud of gas and dust surrounding our young Sun, when the mantle and the core first separated into distinct layers. Current topics of investigation also include the structure and properties of various compounds under the extreme pressures and temperatures found deep inside the planet, and information about the pressure, temperature, and chemical conditions of the mantle that can be gleaned from mineral impurities preserved inside diamonds.

Walter had been at

Guoyin Shen's research interests lie in the quest to establish and to examine models for explaining and controlling the behavior of materials under extreme conditions. His research activities include investigation of phase transformations and melting lines in molecular solids, oxides and metals; polyamorphism in liquids and amorphous materials; new states of matter and their emergent properties under extreme conditions; and the development of enabling high-pressure synchrotron techniques for advancing compression science. 

He obtained a Ph.D. in mineral physics from Uppsala University, Sweden in 1994 and a B.S. in geochemistry from Zhejiang University, China in 1982. For more

Leopoldo Infante became the director of the Las Campanas Observatory on July 31, 2017.

Since 2009, Infante has been the founder and director of the Centre for Astro-Engineering at the Chilean university. He joined PUC as an assistant professor in 1990 and has been a full professor since 2006. He was one of the creators of PUC’s Department of Astronomy and Astrophysics, and served as its director from 2000 to 2006. He also established the Chilean Astronomical Society (SOCHIAS) and served as its president from 2009 to 2010.

Infante received his B.Sc. in physics at PUC. He then acquired a MSc. and Ph.D. in physics and astronomy from the University of Victoria in Canada.