Calendar

Jan
24
Wed
Colloquium Thesis Proposal: Laurel Farris
Jan 24 @ 2:30 pm – 3:30 pm
Colloquium Thesis Proposal: Laurel Farris @ Science Hall, Room 110

Characterizing the oscillatory response of the chromosphere during solar flares

Laurel Farris; NMSU Astronomy Department

Quasi-periodic pulsations (QPPs) are observed in the emission of solar flares over a wide range of wavelengths,

particularly in the radio and hard x-ray regimes where non-thermal emission dominates. These pulsations are

considered to be an intrinsic feature of flares, yet the exact mechanism that triggers them remains unclear.

There have been reports of an increase in the oscillatory power at 3-minute periods (the local acoustic

cutoff frequency) in the solar chromosphere associated with flaring events. I propose to investigate the

chromospheric response to flares by inspecting the spatial and temporal onset and evolution of the 3-minute

oscillatory power, along with any QPP patterns that may appear in chromospheric emission. The analysis

will be extended to multiple flares, and will include time before, during, and after the main event. To test

initial methods, the target of interest was the well-studied 2011 February 15 X-class flare. Data from two

instruments on board the Solar Dynamics Observatory (SDO) were used in the preliminary study, including

continuum images from the Helioseismic and Magnetic Imager (HMI) and UV images at 1600 and 1700

Angstroms from the Atmospheric Imaging Assembly (AIA). Later, spectroscopic data from the Interface

Region Imaging Spectrometer (IRIS) will be used to examine velocity patterns in addition to intensity.

Jan
26
Fri
Colloquium: Zheng Cai (Host: Kristian Finlator)
Jan 26 @ 3:15 pm – 4:15 pm
Colloquium: Zheng Cai (Host: Kristian Finlator) @ BX102

Colloquium Title

Colloquium Speaker Name, Affiliation

Abstract text

Feb
23
Fri
Colloquium Thesis Proposal: Jodi Berdis
Feb 23 @ 3:15 pm – 4:15 pm
Colloquium Thesis Proposal: Jodi Berdis @ BX102

Colloquium Title

Jodi Berdis, NMSU

Abstract text

Feb
26
Mon
Pizza Lunch: Shuo Wang
Feb 26 @ 12:30 pm – 1:30 pm
Pizza Lunch: Shuo Wang @ AY 119
Mar
2
Fri
Colloquium PhD Thesis Defense: Gordon MacDonald
Mar 2 @ 3:15 pm – 4:15 pm
Colloquium PhD Thesis Defense: Gordon MacDonald @ BX102

Colloquium Title

Gordon MacDonald, NMSU

Abstract

Mar
5
Mon
Pizza Lunch: Rene Walterbos
Mar 5 @ 12:30 pm – 1:30 pm
Pizza Lunch: Rene Walterbos @ AY 119
Mar
7
Wed
Colloquium PhD Thesis Defense: Carlos Vargas
Mar 7 @ 3:15 pm – 4:15 pm
Colloquium PhD Thesis Defense: Carlos Vargas @ Science Hall 109

The Relationship Between Star Formation and Matter in Galaxy Halos,

Carlos J. Vargas, NMSU

Abstract text

Mar
9
Fri
Colloquium: Wilson Cauley (Host: Kristen Luchsinger)
Mar 9 @ 3:15 pm – 4:15 pm
Colloquium: Wilson Cauley (Host: Kristen Luchsinger) @ BX102

Multi-pronged investigations into exoplanetary magnetic fields

Wilson Cauley (Arizona State University)

Efforts in exoplanet characterization have led to some very precise determinations of planetary densities, compositions, and even accurate maps of active region and spot locations on stellar surfaces. Exoplanet magnetic fields, however, remain elusive. While radio observations continue to push into the low-mass brown dwarf regime, no emission from a planetary-mass object has been confirmed. I will discuss some of the efforts involving alternate methods for probing exoplanet magnetic fields and how they stack up so far against the prospects for detection via radio emission.

Mar
12
Mon
Pizza Lunch: Caitlin Doughty
Mar 12 @ 12:30 pm – 1:30 pm
Pizza Lunch: Caitlin Doughty @ AY 119

Using CGM metal absorbers to look for galaxies

Mar
15
Thu
Colloquium Thesis Proposal: Drew Chojnowski
Mar 15 @ 3:15 pm – 4:15 pm
Colloquium Thesis Proposal: Drew Chojnowski @ Domenici Hall 102

The Circumstellar Disks and Binary Companions of Be Stars

Drew Chojnowski, NMSU

Tremendous progress has been made over the past two decades toward understanding Be stars, but a number of key aspects of them remain enigmatic. The unsolved mysteries include identification of the mechanism responsible for disk formation, the reason this mechanism occasionally turns off or on unexpectedly, the source of viscosity in the circumstellar disks, and the cause of slowly precessing density perturbations in the disks of many or most Be stars. On a deeper level, the origin of Be stars’ near-critical rotation is unknown, with one possible explanation being spin-up due to interaction with a binary companion. A better understanding of these stars is needed, with a particular focus on high-mass binaries being warranted in the age of gravitational wave astronomy. In this dissertation, I will extend the knowledge and understanding of Be stars through a series of three projects. First, I will present and describe the largest ever homogeneous, spectroscopic sample of Be stars to date. I will then focus on investigation of a rare class of Be stars found in binary systems with hot, low mass companions. The second project will present detailed characterization and modeling of HD~55606, a newly discovered member of this class. Finally, I will discuss the results of spectroscopic monitoring of seven newly discovered systems and establish or place limits on the orbital parameters of the binary components.