The earliest galaxies are those that are most distant. Staff associate Dan Kelson is interested in how these ancient relics evolved. The latest generation of telescopes and advanced spectrographs—instruments that analyze light to determine properties of celestial objects—allow astronomers to accurately measure enormous numbers of distant galaxies. Kelson uses the Magellan 6.5-meter telescopes and high-resolution imaging from the Hubble Space Telescope to study distant galaxies.His observations of their masses, sizes and morphologies allow him to directly measure their stars' aging to infer their formation history. Kelson is the principal investigator of the Carnegie-Spitzer-IMACS Redshift Survey of  very distant and old galaxies. He is also a senior co-investigator of the Cluster Lensing and Supernova with Hubble Multi-Cycle Treasury Program with the Hubble Space Telescope.

This survey of faint galaxies probes the largest unbiased volume of galaxies in the universe when it was 5-10 billion years ago, targeting galaxies more uniformly and over a wide area of the sky. The survey used 100 nights of Magellan time with the Inamori Magellan Areal Camera and Spectrograph, as well as almost 50 nights of 4-meter time at the National Optical Astronomical Observatories.

In order to better understand how galaxies have been forming and evolving over cosmic time, and to specifically interpret the data gathered in the Carnegie-Spitzer-IMACS Redshift Survey, Kelson has also begun development of a new theoretical framework. Using modern mathematical theorems, one can accurately model the evolution of the ensembles of galaxies over time and in groundbreaking ways that will ultimately allow astronomers, for the first time, to empirically decouple the rates of in situ and ex situ mass growth in galaxies.

 Because Kelson's research involves making precision measurements from large quantities of data, he is keenly interested in modern numerical methods and techniques for automating processes for reducing raw data to measured, physical quantities.His work in creating and maintaining the Carnegie Python Distribution currently enables large imaging and spectroscopic datasets to be reduced with little or no human intervention, improving the efficiency of astronomers at Carnegie and around the world.

 Kelson received his B.S. in astronomy and physics from the University of Michigan, Ann Arbor, and his Ph.D. in astronomy from UC-Santa Cruz.  For more information see http://obs.carnegiescience.edu/users/kelson

 

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January 9, 2018

National Harbor, MD—How far away is that galaxy? 

Our entire understanding of the Universe is based on knowing the distances to other galaxies, yet this seemingly-simple question turns out to be fiendishly difficult to answer. The best answer came more than 100 years ago from an astronomer who was mostly unrecognized in her time—and today, another astronomer has used Sloan Digital Sky Survey (SDSS) data to make those distance measurements more precise than ever. 

"It's been fascinating to work with such historically significant stars," says Kate Hartman, an undergraduate from Pomona College who announced the results at today’s American Astronomical Society (AAS) meeting in

Carnegie Science, Carnegie Institution, Carnegie Institution for Science, Sloan Digital Sky Survey, SDSS-IV
January 9, 2018

National Harbor, MD—Astronomers with the Sloan Digital Sky Survey (SDSS) have learned that the chemical composition of a star can exert unexpected influence on its planetary system—a discovery made possible by an ongoing SDSS survey of stars seen by NASA's Kepler spacecraft, and one that promises to expand our understanding of how extrasolar planets form and evolve.

"Without these detailed and accurate measurements of the iron content of stars, we could have never made this measurement," says Robert Wilson, a graduate student in astronomy at the University of Virginia and lead author of the paper announcing the results.

The team presented their results today at the American

December 6, 2017

Pasadena, CA— A team of astronomers led by Carnegie’s Eduardo Bañados used Carnegie’s Magellan telescopes to discover the most-distant supermassive black hole ever observed. It resides in a luminous quasar and its light reaches us from when the universe was only 5 percent of its current age—just 690 million years after the Big Bang. Their findings are published by Nature.

Quasars are tremendously bright objects comprised of enormous black holes accreting matter at the centers of massive galaxies. This newly discovered black hole has a mass that is 800 million times the mass of our Sun.

“Gathering all this mass in fewer than 690 million years is an enormous challenge for

November 22, 2017

SN2015J, a very bright and peculiar supernova, which initially did not have a certain home, now has received its happy ending. 

Discovered on April 27, 2015, by the Siding Springs Observatory in Australia, it was classified as a Type IIn supernova, which is a rare category for this class of objects. But, when it was identified, the "address" entry for this source remained empty, since the galaxy where it exploded was nowhere to be found. For this reason, it was labeled as an "orphan" and was added to the group of 5000 currently known such supernovae.

These mystery supernovae could actually have exploded in the middle of nowhere (away from galaxies), originating from massive

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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.

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.

Guillermo Blanc wants to understand the processes by which galaxies form and evolve over the course of the history of the universe. He studies local galaxies in the “present day” universe as well as very distant and therefore older galaxies to observe the early epochs of galaxy evolution. Blanc conducts a series of research projects on the properties of young and distant galaxies, the large-scale structure of the universe, the nature of Dark Energy—the mysterious repulsive force, the process of star formation at galactic scales, and the measurement of chemical abundances in galaxies.

To conduct this work, he takes a multi-wavelength approach including observations in the UV,

Peter van Keken studies the thermal and chemical evolution of the Earth. In particularly he looks at the causes and consequences of plate tectonics; element modeling of mantle convection,  and the dynamics of subduction zones--locations where one tectonic plate slides under another. He also studies mantle plumes; the integration of geodynamics with seismology; geochemistry and mineral physics. He uses parallel computing and scientific visualization in this work.

He received his BS and Ph D from the University of Utrecht in The Netherlands. Prior to joining Carnegie he was on the faculty of the University of Michigan.

Peter Driscoll studies the evolution of Earth’s core and magnetic field including magnetic pole reversal. Over the last 20 million or so years, the north and south magnetic poles on Earth have reversed about every 200,000, to 300,000 years and is now long overdue. He also investigates the Earth’s inner core structure; core-mantle coupling; tectonic-volatile cycling; orbital migration—how Earth’s orbit moves—and tidal dissipation—the dissipation of tidal forces between two closely orbiting bodies. He is also interested in planetary interiors, dynamos, upper planetary atmospheres and exoplanets—planets orbiting other stars. He uses large-scale numerical simulations in much of his research