Calendar

Nov
6
Mon
Pizza Lunch: Ethan Dederick
Nov 6 @ 12:30 pm – 1:30 pm
Pizza Lunch: Ethan Dederick @ AY 119

Cool Science Results

Nov
9
Thu
Special Pizza Lunch: Jane Rigby
Nov 9 @ 1:00 pm – 2:00 pm
Special Pizza Lunch: Jane Rigby @ AY 119

Galaxy Evolution in High Definition Via Gravitational Lensing

Dr. Jane Rigby

Deputy Project Scientist for JWST, NASA Goddard Space Flight Center

Abstract: In hundreds of known cases, “gravitational lenses” have deflected, distorted, and amplified images of galaxies or quasars behind them.  As such, gravitational lensing is a way to “cheat” at studying how galaxies evolve:  lensing can magnify galaxies by factors of 10–100 times, transforming them from objects we can barely detect to bright objects we can study in detail.   For such rare objects, we are studying how galaxies formed stars at redshifts of 1–4, the epoch when most of the Universe’s stars were formed. For lensed galaxies, we can obtained spectral diagnostics that are currently unavailable for the distant universe, but will become routine with next-generation telescopes.

In particular, I’ll discuss MEGaSaURA, The Magellan Evolution of Galaxies Spectroscopic and Ultraviolet Reference Atlas, which comprises high signal-to-noise, medium spectral resolution (R~3300) spectra of 15 extremely bright gravitationally lensed galaxies at redshifts of 1.6<z<3.6.   The sample, drawn from the SDSS Giant Arcs Survey, are many of the brightest lensed galaxies known.  The MEGaSaURA spectra reveal a wealth of spectral diagnostics: absorption from the outflowing wind; nebular emission lines that will be key diagnostics for JWST, GMT, and TMT; and photospheric absorption lines and P Cygni profiles from the massive stars that power the outflow.

Public Talk: “Preparing to Explore the Universe with the James Webb Space Telescope” – Dr. Jane Rigby (NASA Goddard)
Nov 9 @ 7:00 pm – 8:00 pm
Public Talk: "Preparing to Explore the Universe with the James Webb Space Telescope" - Dr. Jane Rigby (NASA Goddard) @ Gerald Thomas Hall, Room 194

Preparing to Explore the Universe with the James Webb Space Telescope

Dr. Jane Rigby (NASA Goddard, Deputy Project Scientist for JWST)

Abstract: NASA’s James Webb Space Telescope (JWST), scheduled to be launched in 2019, will revolutionize our view of the Universe.  As the scientific successor to the Hubble Space Telescope, JWST will rewrite the textbooks and return gorgeous images and spectra of our universe.   In my talk, I will show how JWST will revolutionize our understanding of how galaxies and supermassive black holes formed in the first billion years after the Big Bang, and how they evolved over cosmic time.  I’ll describe how our international team is preparing for launch, how we decide what targets to observe, and how we are testing the telescope to be sure it will work in space.

More information about the telescope can be found at https://www.jwst.nasa.gov/.

 

 

Nov
10
Fri
Colloquium: Jane Rigby (Host: Moire Prescott)
Nov 10 @ 3:15 pm – 4:15 pm
Colloquium: Jane Rigby (Host: Moire Prescott) @ BX102

Science with the James Webb Space Telescope

Jane Rigby, NASA/GSFC

NASA’s James Webb Space Telescope (JWST) will have revolutionary capabilities and sensitivity for imaging and spectroscopy from 0.7 to 28 micron.  JWST should make major scientific advances across astrophysics, including the physics of reionization, galaxy formation and assembly, planetary science, and extrasolar planets.  In anticipation of a scheduled launch in 2019, JWST Cycle 1 Guest Observer proposals will be due in spring of 2018.  I will review the scientific capabilities of the telescope, the integration and test program, and how observers will plan observations and analyze JWST data.

Nov
13
Mon
Pizza Lunch: James Lewis
Nov 13 @ 12:30 pm – 1:30 pm
Pizza Lunch: James Lewis @ AY 119

Multivariate Analysis of the CGM

Nov
17
Fri
Colloquium: Larisza Krista (Host: James McAteer)
Nov 17 @ 3:15 pm – 4:15 pm

The statistical study of solar dimmings and their eruptive counterparts

Larisza Krista, Cu/CIRES, NOAA/NCEI

Picture1Results are presented from analyzing the physical and morphological properties of 154 dimmings (transient coronal holes) and the associated flares and coronal mass ejections (CMEs). Each dimming in the catalog was processed with the semi-automated Coronal Dimming Tracker (CoDiT) using Solar Dynamics Observatory AIA 193 Å observations and HMI magnetograms. Instead of the typically used difference images, the transient dark regions were detected “directly” in extreme ultraviolet (EUV) images. This allowed us to study dimmings as the footpoints of CMEs—in contrast with the larger, diffuse dimmings seen in difference images that represent the projected view of the rising, expanding plasma. Studying the footpoint-dimming morphology allowed us to better understand the CME structure in the low corona. While comparing the physical properties of dimmings, flares, and CMEs, the relationships between the different parts of this complex eruptive phenomenon were identified: larger dimmings were found to be longer-lived, which suggests that it takes longer to “close down” large open magnetic regions. During their growth phase, smaller dimmings were found to acquire a higher magnetic flux imbalance (i. e., become more unipolar) than larger dimmings. Furthermore, the EUV intensity of dimmings (indicative of local electron density) was found to correlate with how much plasma was removed and how energetic the eruption was. Studying the morphology of dimmings (single, double, fragmented) also helped identify different configurations of the quasi-open magnetic field.

BIO

Dr Larisza Krista received an MSc degree in astrophysics in 2007 from Eotvos Lorand University, in Budapest, Hungary. She did her PhD at Trinity College Dublin (Ireland) as a Government of Ireland Scholar, on “The Evolution and Space Weather Effects of Solar Coronal Holes”. She moved to Boulder in 2011 to accept a research scientist position at CU/CIRES in residence at NOAA/SWPC. She has also been a long-term scientific visitor at the High Altitude Observatory, where she collaborates with Dr Scott McIntosh. Her main interests involve the evolution of open solar magnetic field regions over the solar cycle as well as the related heliospheric structures and geomagnetic effects.

 

 

Nov
27
Mon
Pizza Lunch: Rachel Marra and Trevor Picard
Nov 27 @ 12:30 pm – 1:30 pm
Pizza Lunch: Rachel Marra and Trevor Picard @ AY 119

ASTR 598 Talk

Dec
1
Fri
Colloquium: Laura Keating (Host: Kristian Finlator)
Dec 1 @ 3:15 pm – 4:15 pm
Colloquium: Laura Keating (Host: Kristian Finlator) @ BX102

Colloquium Title

Colloquium Speaker Name, Affiliation

Abstract text

Dec
4
Mon
Pizza Lunch: Karen Kinemuchi
Dec 4 @ 12:30 pm – 1:30 pm
Pizza Lunch: Karen Kinemuchi @ AY 119

Life at Apache Point Observatory

Dec
8
Fri
Colloquium – Dean Pesnell (Host: James McAteer)
Dec 8 @ 3:15 pm – 4:15 pm
Colloquium - Dean Pesnell (Host: James McAteer) @ BX102

SDO, the Sun, the Universe

Dean Pesnell, NASA / GSFC

ABSTRACT: The Sun is our best example for how stars evolve and behave. It is the only star whose surface is well-resolved in time and space. It is the only star which local helioseisomology can look into and through. One tool we to study the Sun is the Solar Dynamics Observatory (SDO), a NASA satellite that has been returning data for seven years. SDO focuses on the variations in the Sun caused by changes in the magnetic field generated by the convection zone.I will describe some aspects of SDO science that can be directly related to Sun-like stars. First are spectral irradiance measurements in extreme ultraviolet wavelengths that contribute to the loss of planetary atmospheres. Next are failed filament eruptions that fall back onto the surface as a form of accretion. Finally, how the magnetic field evolves from solar minimum to maximum and back is giving us clues about predicting that magnetic field. Please come and have a look at how studying the Sun informs our knowledge of stars.