Astrophysics

Amelia Henkel, Graduating President of the Undergraduate Women in Physics Club, speaks about her time at UConn

 

Amelia Henkel, graduating Double Major in Physics and Human Rights, and President of the Undergraduate Women in Physics Club, speaks on the CLAS website about her passion for physics and human rights, and how she mastered challenges in her remarkably interdisciplinary curriculum. “We really need to interact with other disciplines,” says Amelia, “because that’s when physics has the opportunity to make a real impact on the rest of the world.” Her broad research interests range from A to W: from Astronomy to Women’s, Gender, and Sexuality Studies. “Respecting and promoting human rights is a prerequisite to realizing our full potential as human beings,” says Amelia. Physics as a discipline has made progress to become more inclusive, but many groups remain minorities including women. In daily college life in physics departments female students still face “microaggressions and discriminatory practices” which are often unintended and unconscious but nonetheless damaging and frustrating.  As the President of the Undergraduate Women in Physics Club, Amelia helped to organize “events that promote community cohesion and inform the students about the nature of some of the barriers that exist in physics and in STEM, while talking about how we can overcome them.” The recent department-wide event Women in Physics Colloquium organized by Amelia was thought provoking and well-received. The percentage of women earning a Bacheleor’s Degree in Physics from UConn, though slowly increasing and compatible with the national average of about 20% published by APS, is far away from where we wish to be. But the efforts of students like Amelia contribute to improving the situation.  Many thanks to Amelia whose commitment helps to make our department better.

Read more about Amelia on the CLAS website. A short summary of her story is in UConn Today.

Astronomers Assemble View of Evolving Universe

 – Donna Weaver & Ray Villard, Space Telescope Science Institute

The University of Connecticut’s Katherine Whitaker is part of a team of astronomers who have put together the largest and most comprehensive “history book” of the universe from 16 years’ worth of observations from NASA’s Hubble Space Telescope.

This image, a mosaic of nearly 7,500 separate Hubble exposures, presents a wide portrait of the distant universe and contains roughly 265,000 galaxies that stretch back through 13.3 billion years of time to just 500 million years after the universe’s birth in the Big Bang. (Space Telescope Science Institute Image)

The deep-sky mosaic provides a wide portrait of the distant universe, containing 200,000 galaxies that stretch back through 13.3 billion years of time to just 500 million years after the Big Bang. The tiny, faint, most distant galaxies in the image are similar to the seedling villages from which today’s great galaxy star-cities grew. The faintest and farthest galaxies are just one ten billionth the brightness of what the human eye can see.

The image yields a huge catalog of distant galaxies. “Such exquisite high-resolution measurements of the legacy field catalog of galaxies enable a wide swath of extragalactic study,” says Whitaker, the catalog lead researcher. “Often, these kinds of surveys have yielded unanticipated discoveries that have had the greatest impact on our understanding of galaxy evolution.”

The ambitious endeavor, called the Hubble Legacy Field, also combines observations taken by several Hubble deep-field surveys, including the eXtreme Deep Field (XDF), the deepest view of the universe. The wavelength range stretches from ultraviolet to near-infrared light, capturing all the features of galaxy ‘assembly over time.

“Now that we have gone wider than in previous surveys, we are harvesting many more distant galaxies in the largest such dataset ever produced,” says Garth Illingworth of the University of California, Santa Cruz, and leader of the team. “This one image contains the full history of the growth of galaxies in the universe, from their times as infants to when they grew into fully-fledged ‘adults.’”

Illingworth says he anticipates that the survey will lead to an even more coherent and in-depth understanding of the universe’s evolution in the coming years.

The deep-sky mosaic provides a wide portrait of the distant universe, containing 200,000 galaxies that stretch back through 13.3 billion years of time to just 500 million years after the Big Bang.

Galaxies trace the expansion of the universe, offering clues to the underlying physics of the cosmos, showing when the chemical elements originated and enabled the conditions that eventually led to the appearance of our solar system and life.

This new wider view contains 100 times as many galaxies as in the previous deep fields. The new portrait, a mosaic of multiple snapshots, covers almost the width of the full Moon, and chronicles the universe’s evolutionary history in one sweeping view. The portrait shows how galaxies change over time, building themselves up to become the giant galaxies seen in the nearby universe. The broad wavelength range covered in the legacy image also shows how galaxy stellar populations look different depending on the color of light.

The legacy field also uncovers a zoo of unusual objects. Many of them are the remnants of galactic “train wrecks,” a time in the early universe when small, young galaxies collided and merged with other galaxies.

Assembling all of the observations was an immense task. The image comprises the collective work of 31 Hubble programs by different teams of astronomers. Hubble has spent more time on this tiny area than on any other region of the sky, totaling more than 250 days.

The image, along with the individual exposures that make up the new view, is available to the worldwide astronomical community through the Mikulski Archive for Space Telescopes (MAST), an online database of astronomical data from Hubble and other NASA missions.

The new set of Hubble images, created from nearly 7,500 individual exposures, is the first in a series of Hubble Legacy Field images. The team is working on a second set of images, totaling more than 5,200 Hubble exposures, in another area of the sky.

In addition, NASA’s upcoming James Webb Space Telescope will allow astronomers to push much deeper into the legacy field to reveal how the infant galaxies actually grew. Webb’s infrared coverage will go beyond the limits of Hubble and Spitzer to help astronomers identify the first galaxies in the universe.

The Hubble Legacy Fields program, supported through AR-13252 and AR-15027, is based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy Inc., under NASA contract NAS 5-26555.

This article first appeared in UConn Today on May 2, 2019.

Professor Rainer Weiss: Katzenstein Distinguished Lecture

The Katzenstein Distinguished Lectures series continued in the 2018 academic year with its twenty second Nobel Laureate lecturer, with an October 26, 2018 lecture by Professor Rainer Weiss of the Massachusetts Institute of Technology.

The title of Professor Weiss’ talk was “Exploration of the Universe with Gravitational Waves”, with abstract:

The observations of gravitational waves from the merger of binary black holes and from a binary neutron star coalescence followed by a set of astronomical measurements is an example of investigating the universe by “multi-messenger” astronomy. Gravitational waves will allow us to observe phenomena we already know in new ways as well as to test General Relativity in the limit of strong gravitational interactions – the dynamics of massive bodies traveling at relativistic speeds in a highly curved space-time. Since the gravitational waves are due to accelerating masses while electromagnetic waves are caused by accelerating charges, it is reasonable to expect new classes of sources to be detected by gravitational waves as well. The lecture will start with some basic concepts of gravitational waves, briefly describe the instruments and the methods for data analysis that enable the measurement of gravitational wave strains of one part in 10 to the 21, and then present the results of recent runs. The lecture will end with a vision for the future of gravitational wave astrophysics and astronomy.

Students discuss gravitational waves with Prof. Weiss (MIT) following lecture

In 2017 Professor Weiss shared the Nobel Prize in Physics with Professor Kip Thorne and Professor Barry Barish for their epochal discovery of gravitational waves, waves that had been predicted by Albert Einstein using his General Theory of Relativity no less than a hundred years before.

Professor Rainer Weiss received his BS degree from MIT in 1955 and his PhD from MIT in 1962. He was on the faculty of Tufts University from 1960 to 1962, and did post-doctoral research at Princeton from 1962 to 1964. He joined the MIT faculty in 1964 and remained a regular faculty member there until he became emeritus in 2001. Along with Kip Thorne, the late Ronald Drever and Barry Barish he spearheaded the development of LIGO, the Laser Interferometer Gravitational-Wave Observatory, a set of two interferometers, one located in Louisiana and the other in Washington State. The interferometers would jointly look for gravitational wave signals seen in coincidence, and in September 2015 made the very first detection of gravity waves. At Louisiana State University he has served as an Adjunct Professor of Physics since 2001. As well as research in gravity waves Professor Weiss’ other primary interests are in atomic clocks and cosmic microwave background measurements.

Dr. Weiss had previously visited the University of Connecticut in Fall 2015 as part of a lecture series that fall given at the University of Connecticut in commemoration of the hundredth year of Einstein’s development of his Theory of General Relativity. At that time Dr. Weiss described the ongoing search at LIGO for gravity waves produced by the merger of two black holes. And the initial announcement of a discovery was made in February 2016, shortly after Dr. Weiss’s visit to the University of Connecticut. It is also of interest to note that Dr. Shep Doeleman of Harvard University was another of the speakers at the Fall 2015 University of Connecticut Einstein commemoration. He talked about the ongoing effort to actually detect the event horizons associated with black holes using the Event Horizon Telescope, black holes being yet another prediction of Einstein’s Theory that was also one hundred years old. And in 2019 Dr. Doeleman announced the very the first direct detection of a black hole event horizon. Thus, with the first detection of gravity waves produced by black hole mergers and then the detection of an event horizon itself, the theory of black holes is put on a very secure observational foundation. This lecture can be viewed: https://www.uctv14.com/ucspanblog/2018/12/10/katzenstein-distinguished-lecture-october-26th-2018?rq=Katzenstein