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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June 29, 2021

Washington, DC—A team of Carnegie astronomers was awarded $1.4 million from the Heising-Simons Foundation to develop an ambitious and versatile infrared spectrograph for the Magellan telescopes at Carnegie’s Las Campanas Observatory in Chile that will enable breakthroughs in understanding cosmology, galaxy evolution, and exoplanet atmospheres.

Spearheaded by instrument lead Nicholas Konidaris and project scientists Andrew Newman and Gwen Rudie of the Carnegie Observatories, the project, called the Magellan Infrared Multiobject Spectrograph, or MIRMOS, will expand researchers’ view of the sky in the infrared wavelengths of the spectrum and significantly advance

NG4321 galaxy. Credit: ALMA (ESO/NAOJ/NRAO)/PHANGS, S. Dagnello (NRAO)
June 8, 2021

Pasadena, CA—A team of astronomers, including Carnegie’s Guillermo Blanc, used the  Atacama Large Millimeter/submillimeter Array (ALMA) to complete the first census of molecular clouds in the nearby universe, revealing that contrary to previous scientific opinion, these stellar nurseries do not all look and act the same. In fact, they’re as diverse as the people, homes, neighborhoods, and regions that make up our own world. 

Stars are formed out of clouds of dust and gas called molecular clouds, or stellar nurseries. Each stellar nursery in the universe can form thousands or even tens of thousands of new stars during its lifetime. Between 2013 and 2019

This artist's impression of the quasar P172+18. Credit: ESO/M. Kornmesser.
March 8, 2021

Pasadena, CA— The Magellan Baade telescope at Carnegie’s Las Campanas Observatory played an important role in the discovery of the most-distant known quasar with a bright radio emission, which was announced by a Max Planck Institute for Astronomy in Heidelberg and European Southern Observatory-led team and published in The Astrophysical Journal. One of the fastest-growing supermassive black holes ever observed, it is emitting about 580 times the energy as the entire Milky Way galaxy.

Quasars are incredibly luminous supermassive black holes accreting matter at the centers of massive galaxies. Their brightness allows astronomers to study them in detail even at great

3D spatial distribution of 16 spectroscopically confirmed proto-clusters.
February 12, 2021

Las Campanas Observatory—When the universe was about 350 million years old it was dark: there were no stars or galaxies, only neutral gas—mainly hydrogen—the residue of the Big Bang. That foggy period began to clear as atoms clumped together to form the first stars and the first quasars, causing the gas to ionize and high-energy photons to travel freely through space. 

This epoch, called the “reionization” epoch, lasted about 370 million years and the first large structures in the universe appear as groups or clusters of galaxies. 

An international team of astronomers grouped in the LAGER consortium (Lyman Alpha Galaxies in the Epoch

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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

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

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/

Johanna Teske became the first new staff member to join Carnegie’s newly named Earth and Planets Laboratory (EPL) in Washington, D.C., on September 1, 2020. She has been a NASA Hubble Fellow at the Carnegie Observatories in Pasadena, CA, since 2018. From 2014 to 2017 she was the Carnegie Origins Postdoctoral Fellow—a joint position between Carnegie’s Department of Terrestrial Magnetism (now part of EPL) and the Carnegie Observatories.

Teske is interested in the diversity in exoplanet compositions and the origins of that diversity. She uses observations to estimate exoplanet interior and atmospheric compositions, and the chemical environments of their formation

Phillip Cleves’ Ph.D. research was on determining the genetic changes that drive morphological evolution. He used the emerging model organism, the stickleback fish, to map genetic changes that control skeletal evolution. Using new genetic mapping and reverse genetic tools developed during his Ph.D., Cleves identified regulatory changes in a protein called bone morphogenetic protein 6 that were responsible for an evolved increase in tooth number in stickleback. This work illustrated how molecular changes can generate morphological novelty in vertebrates.

Cleves returned to his passion for coral research in his postdoctoral work in John Pringles’ lab at Stanford

Brittany Belin joined the Department of Embryology staff in August 2020. Her Ph.D. research involved developing new tools for in vivo imaging of actin in cell nuclei. Actin is a major structural element in eukaryotic cells—cells with a nucleus and organelles —forming contractile polymers that drive muscle contraction, the migration of immune cells to  infection sites, and the movement of signals from one part of a cell to another. Using the tools developed in her Ph.D., Belin discovered a new role for actin in aiding the repair of DNA breaks in human cells caused by carcinogens, UV light, and other mutagens.

Belin changed course for her postdoctoral work, in

Evolutionary geneticist Moises Exposito-Alonso joined the Department of Plant Biology as a staff associate in September 2019. He investigates whether and how plants will evolve to keep pace with climate change by conducting large-scale ecological and genome sequencing experiments. He also develops computational methods to derive fundamental principles of evolution, such as how fast natural populations acquire new mutations and how past climates shaped continental-scale biodiversity patterns. His goal is to use these first principles and computational approaches to forecast evolutionary outcomes of populations under climate change to anticipate potential future