Calendar

Jan
19
Sat
Cume #430
Jan 19 @ 9:30 am – 12:00 pm
Jan
20
Sun
Lunar Eclipse – Public Outreach Event
Jan 20 @ 7:45 pm – 10:30 pm
Lunar Eclipse - Public Outreach Event

The NMSU Astronomy Department will be holding a two-part public event for the January 20th total lunar eclipse!

Starting at 7:45 PM, Professor Kristian Finlator will give a talk on the eclipse in the Biology Annex (located here) from 7:45 PM to 8:15 PM, with a second provisional talk planned at 8:30 PM in case attendance is too high for everyone to fit into the room for the first talk.

From 8:30 pm to 10:30 PM the telescopes at Tombaugh Observatory (located here, a short walk/drive from the Biology Annex) will be opened and graduate students will be on hand to answer questions and run the telescopes. Feel free to come to one or both of these events, or to arrive to the telescopes at any time between 8:30 and 10:30. Please keep in mind, the eclipse begins around 8:30, but totality (or, when the moon turns red from fully entering Earth’s shadow) doesn’t begin until ~9:40 PM. The Society of Astronomy Students will also be on site with hot chocolate!

Parking is available at both locations. If there is a possibility of inclement weather, please call the Observatory Hotline (575-646-6278) to make sure that we will have the telescopes open (if there’s a chance of rain, we will not open the telescopes, and we will leave a message at this number saying so).

Jan
21
Mon
ASTR 616 – Galaxies II
Jan 21 @ 10:30 am – 11:45 am
PDS Atmospheres Node meeting
Jan 21 @ 3:30 pm – 4:30 pm
PDS Atmospheres Node meeting @ AY 119

Detailed Node Meeting Schedule:

1/07: ELSA & Node
1/14: ELSA
1/21: nothing – MLK holiday
1/28: Node
2/04: ELSA
2/11: Node
2/18: ELSA
2/25: Node
3/04: ELSA
3/11: Node
3/18: ELSA (but Lynn not here, LPSC)
3/25: nothing – Spring Break
4/01: Node
4/08: ELSA
4/15: Node
4/22: ELSA
4/29: Node
5/06: nothing – Final Exams week
5/13: ELSA

Jan
22
Tue
ASTR 610 – Radio Astronomy
Jan 22 @ 10:30 am – 11:45 am
ASTR 506 – Stellar Dynamics and Hydrodynamics
Jan 22 @ 12:00 pm – 1:15 pm
Jan
23
Wed
ASTR 616 – Galaxies II
Jan 23 @ 10:30 am – 11:45 am
Astro-ph Discussion
Jan 23 @ 1:30 pm – 2:00 pm
Astro-ph Discussion @ AY119
Colloquium Thesis Defense: Lauren Kahre
Jan 23 @ 3:00 pm – 4:00 pm
Colloquium Thesis Defense: Lauren Kahre

Extinction Mapping and Dust-to-Gas Ratios of Nearby Galaxies

Lauren Kahre, NMSU

We present a study of the dust{to{gas ratios in 31 nearby (D >
10 Mpc) galaxies. Using Hubble Space Telescope broad band WFC3/UVIS UV and
optical images from the Treasury program LEGUS (Legacy ExtraGalactic UV
Survey) combined with archival HST/ACS data, we correct thousands of
individual stars for extinction across these galaxies using an
isochrone-matching (reddening-free Q) method. We generate extinction maps
for each galaxy from the individual stellar extinctions using both
adaptive and fixed resolution techniques, and correlate these maps with
neutral HI and CO gas maps from literature, including The HI Nearby Galaxy
Survey (THINGS) and the HERA CO-Line ExtraGalactic Survey (HERACLES). We
calculate dust-to-gas ratios and investigate variations in the dust-to-gas
ratio with galaxy metallicity. We find a power law relationship between
dust-to-gas ratio and metallicity. The single power law is consistent with
other studies of dust-to-gas ratio compared to metallicity, while the
broken power law shows a significantly shallower slope for low metallicity
galaxies than previously observed. We find a change in the relation when
H_2 is not included. This implies that underestimation of N_H2 in
low-metallicity dwarfs from a too-low CO-to-H2 conversion factor X_CO
could have produced too low a slope in the derived relationship between
dust-to-gas ratio and metallicity. We also
compare our extinctions to those derived from fitting the spectral energy
distribution (SED) using the Bayesian Extinction and Stellar Tool (BEAST)
for NGC 7793 and and systematically lower extinctions from SED-fitting as
compared to isochrone matching. Finally, we compare our extinction maps of
NGC 628 to maps of the dust obtained via IR emission from Aniano et al.
(2012) and find a factor of 2 difference in dust-to-gas ratios determined
from the two maps, consistent with previous work.

Jan
24
Thu
ASTR 610 – Radio Astronomy
Jan 24 @ 10:30 am – 11:45 am