The entire universe—galaxies, stars, and planets—originally condensed from a vast network of tenuous, gaseous filaments, known as the intergalactic medium, or the gaseous cosmic web. Most of the matter in this giant reservoir has never been incorporated into galaxies; it keeps floating about in intergalactic space, largely in the form of ionized hydrogen gas.

 Michael Rauch is interested in all aspects of the intergalactic medium. He uses large telescopes, like the Magellans, to take spectra—light that reveals the chemical makeup of distant objects— of background quasars, which are highly energetic and extremely remote. He is looking for evidence of gas clouds located between the quasars and us. The hundreds of spectral absorption lines between us and each quasar—often referred to as the Lyman alpha forest—record changes in the cosmic web from the earliest galaxies to the present. Rauch and his collaborators have determined many of the basic properties of the intergalactic medium, including its matter density, temperature, chemistry, the small-scale density structure, and most recently, the turbulent motion in the gas.

 With his theorist colleagues, Rauch has also proposed and evaluated models for the interpretation of quasar spectra in the context of galaxy formation. He has participated in an observational survey of gravitationally lensed quasars and close pairs to study the large-scale motions in the gas. He wants to understand how the cosmic web follows the general expansion of the universe, how it stretches and contracts, and how it is funneled into future galaxies. Galaxies not only take in gas, they also return processed and chemically enriched matter back to the extragalactic realm. Rauch hopes to quantify the environmental impact of galaxies on the surrounding intergalactic medium.

Rauch also is performing ultra-deep experimental searches for faint radiation emitted by very distant, so-called high redshift galaxies and by the intergalactic medium itself. These observations may ultimately allow the construction of detailed images of the distribution of matter in the young universe.

Rauch received his undergraduate degree in physics from Gutenberg University in Germany, and a Ph. D. in astronomy from Cambridge University. From 1992 to 1995 he was a research associate at Carnegie then went to Caltech as a Hubble Fellow until 1998, when he became a staff astronomer at the European Southern Observatory before joining Carnegie as a staff astronomer. For more information see http://obs.carnegiescience.edu/users/mr

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August 9, 2018

Washington, D.C.—Observatories NASA Hubble Postdoctoral Fellow Maria Drout will receive the tenth Postdoctoral Innovation and Excellence Award (PIE). These awards are made through nominations from the departments and are chosen by the Office of the President. The recipients are awarded a cash prize for their exceptionally creative approaches to science, strong mentoring, and contributing to the sense of campus community.

Maria Drout was one of four Carnegie astronomers who, along with colleagues from UC Santa Cruz, provided the first-ever glimpse of two neutron stars colliding last August. She was first author on a Science paper, which measured the changing light from that merger

August 2, 2018

Pasadena, CA—What happens when a star behaves like it exploded, but it’s still there?

About 170 years ago, astronomers witnessed a major outburst by Eta Carinae, the brightest known star in our Milky Way galaxy. The blast unleashed almost as much energy as a standard supernova explosion.

Yet, Eta Carinae survived.

An explanation for the eruption has eluded astrophysicists, but Carnegie telescopes played an important role in solving the mystery.

Researchers can’t t a time machine back to the mid-1800s to observe the outburst with modern technology. However, astronomers can use nature’s own “time machine,” courtesy of the fact that light travels at a finite

This artist’s impression shows the temperate planet Ross 128 b, with its red dwarf parent star in the background. It is provided courtesy of ESO/M. Kornmesser.
July 10, 2018

Pasadena, CA—Last autumn, the world was excited by the discovery of an exoplanet called Ross 128 b, which is just 11 light years away from Earth. New work from a team led by Diogo Souto of Brazil’s Observatório Nacional and including Carnegie’s Johanna Teske has for the first time determined detailed chemical abundances of the planet’s host star, Ross 128.

Understanding which elements are present in a star in what abundances can help researchers estimate the makeup of the exoplanets that orbit them, which can help predict how similar the planets are to the Earth.

“Until recently, it was difficult to obtain detailed chemical abundances for this kind of star,” said lead

An artist’s conception of a radio jet spewing out fast-moving material from the newly discovered quasar. Artwork by Robin Dienel, courtesy of Carnegie Institution for Science.
July 9, 2018

Pasadena, CA—Carnegie’s Eduardo Bañados led a team that found a quasar with the brightest radio emission ever observed in the early universe, due to it spewing out a jet of extremely fast-moving material.

Bañados’ discovery was followed up by Emmanuel Momjian of the National Radio Astronomy Observatory, which allowed the team to see with unprecedented detail the jet shooting out of a quasar that formed within the universe’s first billion years of existence. 

The findings, published in two papers in The Astrophysical Journal, will allow astronomers to better probe the universe’s youth during an important period of transition to its current state.

Quasars are comprised

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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.

The Ludington lab investigates complex ecological dynamics from microbial community interactions using the fruit fly  Drosophila melanogaster. The fruit fly gut carries numerous microbial species, which can be cultured in the lab. The goal is to understand the gut ecology and how it relates to host health, among other questions, by taking advantage of the fast time-scale and ease of studying the fruit fly in controlled experiments. 

Nick Konidaris is a staff scientist at the Carnegie Observatories and Instrument Lead for the SDSS-V Local Volume Mapper (LVM). He works on a broad range of new optical instrumentation projects in astronomy and remote sensing. Nick's projects range from experimental to large workhorse facilities. On the experimental side, he recently began working on a new development platform for the 40-inch Swope telescope at Carnegie's Las Campanas Observatory that will be used to explore and understand the explosive universe.

 Nick and his colleagues at the Department of Global Ecology are leveraging the work on Swope to develop a new airborne spectrograph that will be used to provide a direct

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