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Protoplanetary Disks in Orion

A group of UA scientists ( Steward Professor Josh Eisner, Associate Astronomer Serena Kim, Steward Postdocs Nick Ballering and  Min Fang, Steward Grad Student Ryan Boyden, and LPL Associate Professor Ilaria Pascucci) and their collaborators have used the ALMA telescope to image protoplanetary disks in the Orion star forming region. You can read the press release HERE. Josh Eisner has kindly written a couple of paragraphs that you can read below.

"Protoplanetary disks are the birth-sites of planets.  A team of scientists led by the University of Arizona has imaged a cluster of protoplanetary disks in the Orion Nebula and discovered that they are smaller than those previously studied in closer, less-dense regions. These disks are similar in size to theoretical models for the protosolar nebula.

Given that our own solar system (and most systems in the Galaxy) likely formed in an Orion-like environment, this finding suggests that we may be observing typical planetary systems in the making.

 The team's findings have been published in the Astrophysical Journal. The scientists used the largest telescope in the world, an interferometric array of radio telescopes in Chile called ALMA, to observe about 110 protoplanetary disks in the Orion Nebula in the deepest survey of the region yet.  Based on the images, the team was able to calculate the masses and sizes of protoplanetary disks in the Orion Nebula.  Their survey showed that Orion, with its massive stars and high stellar density, has disks that look significantly different than those in nearby, but less-dense regions.  To confirm the effects of environment on the star and planet formation process, U of A scientists are pursuing grant funding and telescope time to study more regions of dense, high-mass star formation."


Image: NASA, ESA, M. Robberto of STScI/ESA, HST Orion Treasury project team, and L. Ricci ESO

Steward Grad Student Ekta Patel and Steward Assistant Professor Gurtina Besla are the lead authors of a study to use the best-available observational data and physically conserved quantities to place robust limits on the mass of the Milky Way. Ekta provides the following text:

"Calculating the mass of our galaxy precisely is important for our understanding of galaxy physics, but it is difficult to do since we live inside of the Milky Way. The current widely-accepted theory on the growth of structures in our universe is the cold dark matter theory. This theory predicts that Milky Way mass galaxies should host around 100-200 satellite galaxies, or galaxies that orbit other galaxies. Currently, we know of about 50 satellite galaxies orbiting our own, so one reason a precise mass estimate is useful is to test how well this theory matches our observations in the context of the satellite galaxy population.

Many values of the Milky Way's mass, including some 30-year-old results from Steward astronomers, have been published over the last few decades using different methods. In this work, we present a method that appears to be robust when we use the information available to us and we hope that it will be a way to move forward as the observational data sets continue to grow and as numerical simulations of the universe improve. This method focuses on using the orbital angular momentum of satellite galaxies rather than their position and velocity to construct a mass estimate for the Milky Way. The benefit of using angular momentum is that it is conserved over time, unlike position and velocity. This means that no matter where a satellite galaxy might be in its orbit around its host galaxy (i.e. closest approach or farthest distance), the method still proves to be reliable. The second benefit of our method is that we use the properties of eight or nine Milky Way satellite galaxies simultaneously, which helps in yielding a more precise estimate. As the properties of additional Milky Way satellites are measured, we will be able to revise our current Milky Way mass estimate, which is about 960 billion times the mass of the Sun."

The UA press release can be found HERE.

The cover photo had to be trimmed to fit. To see Yuri Beletsky's full-size photo of the Milky Way with two of its satellite galaxies (the two Magellanic Clouds), click here. To see many more of his photos, go HERE.


Students Help Little Telescope Do Big Things

A four-year effort involving Kitt Peak's Bok Telescope and UA students helped a team of astronomers measure the masses of a large sample of supermassive black holes. Despite its modest size and advanced age of almost 50 years, the instrument keeps churning out big science.

UA Senior Named 2018 Churchill Scholar

Namrah Habib is one of 16 students to receive a Churchill Scholarship, which will allow her to pursue a Master of Philosophy in Astronomy at the University of Cambridge.

UA Leads Project on Big Data and Black Holes

A worldwide collaboration will work on ways of processing unprecedented amounts of data in real time, with a primary goal of assisting the effort to take the first-ever pictures of a black hole. However, applications eventually could include self-driving cars, renewable energy and national defense.

Bok to the Future: Sounding the Depths of a Dying Star

A small, aging telescope — the Bok Telescope on Kitt Peak — can still do mighty science, even helping astrophysicists undertake a virtual journey to the center of a dead star.

The GMTO has shared a 360 degree panorama taken by a drone. You can pan, zoom in and out, and start the video using the controls. The GMT is a partnership of (alphabetically) Arizona State University, Astronomy Australia Limited, Australian National University, Carnegie Observatories, The São Paulo Research Foundation – FAPESP, Harvard University, Korea Astronomy and Space Science Institute (KASI), the Smithsonian Institution, Texas A&M University, The Department of Astronomy of the University of Texas at Austin, The University of Arizona, and the University of Chicago. GMTO recently entered into an agreement with the NSF, NOAO, and the Thirty Meter Telescope International Observatory to seek federal funding and to give access to non-partner-institution astronomers.


On May 11, 2018, Astronomy/Steward graduated ten Astronomy majors, seventeen Astronomy minors, and hooded five PhD students.

Below we show eight photos, all of which can be enlarged by clicking. Photos are courtesy of Michelle Cournoyer and Marina Dunn.

Majors: Tyler Baines; Rafia Bushra; Jenny Calahan; Quadry Chance; Marina Dunn; Aidan Gibbs; Andrew Henrici; Frida Jauregui; Andrew Weldon; Nicole Zawadzki.

Minors: Andrew Brewer; Cody Dalton; Taylor East; Ryan Hamilton; Morgan Harlan; Elizabeth Kinney; Alexis Lugo; Seth Martin; Raul Moraga, III; Liam Murphy; Will Nelson; Angelo Pama; Gordon Ramsbottom, III; Lennon Reinhart; Kimberly Rodas; Linden Willems; Mindi Zudekoff.

PhDs: Melissa Halford; Ben Rackham; J. T. Schindler; Brian Svoboda; Ya-Lin Wu.

From left to right: Graduate students are Brian Svoboda, Melissa Halford, Benjamin Rackman, Jan-Torge Schindler. Undergraduates are Aidan Gibbs, Quadry Chance, Nicole Zawadzki, Marina Dunn, Jenny Calahan, Frida Jauregui, Tyler Baines, Andrew Weldon, Rafia Bushra. 

Jenny Calahan giving Outstanding Senior in Astronomy speech at the College of Science Commencement Ceremony.

Quadry Chance, Nicole Zawadzki, Marina Dunn, and Jenny Calahan.

Jenny Calahan, Nicole Zawadzki, and Marina Dunn.

Ya-Lin Wu, Brian Svoboda, and Jan-Torge Schindler after the ceremony.

Advisor Laird Close and advisee Ya-Lin Wu.

Advisor Dennis Zaritsky and advisee Melissa Halford.

On May 3, we had a a celebration and ceremony for graduating Majors and Minors. Pictured here are  (left to right) Nicole Zawadzki, Marina Dunn,  Andrew Henrici, Jenny Calahan, Undergrad Studies Program Coordinator Dr Yancy Shirley, Jeffrey Hamilton, Andrew Weldon, Aidan Gibbs, Tyler Baines, Frida Jauregui, Angelo Pama, Quadry Chance, Dr Tom Fleming, William Nelson, and Head of the Dept of Astronomy Buell Jannuzi.

left:courtesy M3 Engineering and TMT International Observatory LLC; right: courtesy GMT Mason Media and GMT Project

On Monday, May 21, 2018, it was announced that the GMT project, the Thirty Meter International Observatory, and NOAO and the NSF have joined forces. HERE is the press release from NOAO from which we quote a few paragraphs (the photos come from TMT and GMT websites):

"Our shared mission is to strengthen scientific leadership by the U.S. community-at-large through access to extremely large telescopes in the Northern and Southern Hemispheres. This two-hemisphere model will provide the U.S. science community with greater and more diverse research opportunities than can be achieved with a single telescope, and hence more opportunities for leadership.

Our immediate task is advocacy for frontier research programs led by U.S community scientists that can achieve exceptional advancements in humanity’s understanding of the cosmos.

Our audience is the U.S. research community as represented by the upcoming Decadal Survey of Astronomy and Astrophysics (an enterprise of the U.S. National Academies).

As an essential part of that immediate task, we will work with the U.S. research community to develop exemplar Key Science Programs (KSPs) within major research areas including the dark universe, first stars & first galaxies, exoplanet atmospheres, the surfaces of satellites and other small bodies throughout Solar System, and/or other topics to be proposed and prioritized by community-based working groups.

Key Science Programs are envisioned to be open collaborations that gather observers, theorists, and data scientists together to exploit significant investments of Thirty Meter Telescope (TMT) and Giant Magellan Telescope (GMT) observing time, from tens to hundreds of nights. Some of these collaborations are expected to be international in nature. If well-justified by KSP plans, we envisage that at least 25% of the observing time at each international observatory will be available for the U.S. community."


8/20/2018: Fall Semester Classes Start

Monday, August 20, 2018 (All day)

First Day of Fall Semester


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