by Victor Davis, Program Chair
March at Peyton Hall
The March, 2024 meeting of the AAAP will take place (we dare to hope) in Peyton Hall on the campus of Princeton University on Tuesday, March 12th at 7:30 PM. As usual, the meeting is open to AAAP members and the public. Participants can join the meeting in-person at Peyton Hall or log in to the Zoom session as early as 7:00 pm to chat informally before the meeting begins. This evening’s guest speaker is Erika Bernadette Hoffman, a 3rd-year Astronomy PhD student at the University of Maryland, College Park, and a graduate researcher at NASA’s Goddard Space Flight Center. Her talk will be “Supermassive Black Hole Winds: An X-ray Perspective.”
Options for Attending the Meeting
You may choose to attend the meeting in person or participate via Zoom or YouTube as we’ve been doing for the past few years. (See How to Participate below for details). Due to security concerns, if you log in before the host has set up internet connectivity in Peyton Hall, you may need to wait in the Waiting Room for a few minutes until the host is prepared to admit you into the meeting. You’ll need to unmute yourself to make comments or ask questions. It’s polite, though not required, for you to enable your camera so other participants can see you. A week or so after the meeting, the video of the lecture and Q&A will be posted on AAAP’s public YouTube channel.
Meet the Speaker Dinner
The club will host a “Meet the Speaker” dinner at Winberie’s Bar and Restaurant, 1 Palmer Square, Princeton, NJ, just across the street from the campus of Princeton University. The reservation is prior to the meeting on March 12th at 5:45 pm. Please contact the Program Chair if you plan to attend.
Here’s the anticipated agenda for March, 2024’s monthly meeting of the AAAP:

Getting to Peyton Hall
The parking lots across the street (Ivy Lane) from Peyton Hall are now construction sites, unavailable for parking. We’ve been advised by the administration of the astrophysics department that we should park in the new enclosed parking garage off Fitzrandolph street and walk around the stadium and athletic fields. Here’s a map of the campus and walking routes from the parking garage to Peyton Hall. The map shows the recently completed East Garage. Not shown is an access road Sweet Gum that connects from Faculty Road to an entrance at the lower left corner of the garage. Stadium Road connects from Fitzrandolph Road to another entrance at the opposite corner (and higher level) of the garage. It’s about a 10-15 minute walk from the parking garage to Peyton Hall.


Featured Speaker:
Erika Bernadette Hoffman
Graduate Student
University of Maryland, College Park
ebhoff@umd.edu
“Supermassive Black Hole Winds:
An X-ray Perspective”
Supermassive black holes (SMBH) at the centers of galaxies play a pivotal role in the evolution of the galaxy they reside in, but the physics to explain how this occurs remains poorly understood. As nearby matter is attracted to a black hole, it forms a hot, dense disk in which some particles can eventually shed enough energy via friction to fall into the black hole, a process known as accretion. Intensely accreting supermassive black holes, also called Active Galactic Nuclei (AGN), are the most luminous, persistent astronomical sources in the sky, so bright they can outshine all the stars in their galaxy. Their outflowing radiation coupled with disk matter being ejected away as jets and winds yields a surprisingly difficult environment for SMBHs to gain mass and have drastic effects on their surrounding galaxies. In this talk, I will discuss how specifically high-energy disk winds launched from close to the black hole, detectable via their interactions with X-rays, have a strong potential to explain SMBH-galaxy relationships. Although these regions are too small and distant to resolve in images, we can determine key wind properties by analyzing high-resolution X-ray spectroscopic observations. Obtaining measurements from this data can be challenging since it requires complex physical and statistical calculations. However, recent improvements in models, methods, computing power, and the new data from the recently launched X-ray Imagining and Spectroscopy Mission (XRISM), can give us completely new, key insights into the underlying physics and overall impact of SMBH winds on galaxies.
Erika Bernadette Hoffman
Erika attended community college in her home state of California at Irvine Valley College and then went on to receive a B.S. in Astrophysics at the University of California, Los Angeles. She received her M.S. in Astronomy at UMD. Before becoming an astrophysics researcher who can do her work entirely from her laptop, she used to stargaze in the Mojave Desert and has even spent time observing from the historic Mount Wilson Observatory, where Edwin Hubble worked.
While at UCLA, Erika did astronomical instrumentation research for the Near-Infrared Spectrometer on the Hawaii Keck Telescopes, which resulted in a publication in the proceedings of the International Society for Photonics and Optics (SPIE). In graduate school, she now uses X-ray data to study one of her greatest passions, supermassive black holes and their relationships with their host galaxies.
Her other great passion is advocating for equity, diversity, inclusion, (EDI) accessibility, and social justice, especially in science education and academia. She is currently a member of the UMD Astronomy EDI committee. As a science communicator online, particularly TikTok, Erika discusses physics and astronomy concepts, as well as the social contexts in which people learn and research physics. Erika emphasizes that just as scientists must characterize and address the biases and limitations of their instruments, we must also do the same with our own institutions and minds.
How to Participate (Links)
Zoom
Join Zoom Meeting
https://us06web.zoom.us/j/89107290058?pwd=Lo4xSMdV1vQR9vWgsHfHHMZyuJLA6h.1
YouTube
https://youtube.com/live/7jBYj-3eLoc
A look ahead at future guest speakers:
| Date | Featured Speaker | Topic | |
| April 9 2024 | Eclipse Observations![]() | Since this meeting will take place the day after the Total Solar Eclipse of 08 April 2024, and many members will be out of town or returning from their trips, I’m suggesting that we host an online roundup of eclipse observations, with members (and perhaps others) Zooming in to share their experiences. | |
| May 14 2024 | Dr. Tea Temim![]() Research Astronomer, Princeton University Department of Astrophysics | Dr. Temim will describe her research using JWST imagery to study supernova remnants. Suggested by Gene Allen. temim@astro.princeton.edu | |
| June 11 2024 | NJ State Museum planetarium’s Bill Murray, and Jacob Hamer, Assistant Curator![]() | AAAP’s traditional annual pilgrimage to the NJ State Museum planetarium in Trenton, where members will experience a presentation and a preview of the planetarium’s latest sky show. |
As always, members’ comments and suggestions are gratefully accepted and much appreciated.
victor.davis@verizon.net
program@princetonastronomy.org
(908) 581-1780 cell



Title: Under Alien Skies: A Sightseer’s Guide to the Universe











The current expansion which is accelerating (right portion of the picture) is supposed to be caused by Dark energy. Also known as the energy of the vacuum, wherein virtual particles come into existence and get annihilated, not much is known about it, There has been no light shed on the “dark” yet. In the middle of such a situation comes in an explanation based on Multiverses or Multiple Universes. While the Multiverse is only a mathematical theory, it is also being used to explain what happened before the Big Bang. Very well explained in the book “Before the Big Bang” by Laura Mersini-Houghton. It is posited that multiple Universes float in a higher dimension. Universes are born and not everyone of them matures to become one like ours.
Studying the pattern of CMB (Cosmic Microwave Background) radiation can give us some clues. Like the book “Before the Big Bang” mentioned that a patch of the pattern in CMB was possibly related to interaction with our neighboring Universes (picture shown below has a circled patch in the right lower corner, by the Planck satellite, courtesy Physics World). There could be other hidden messages in the CMB patterns. CMB could tell us about possible mergers with other Universes. I am letting my imagination fly here. Someday we might find out there is no dark matter at all. The gravitational effects we see may be due to the tug of our neighboring Universe ! Both the “darks’ ‘ which are not well understood – dark energy and dark matter may be due to a common cause of the multiverse.













