A special Astro lunch, several of our department members will report on their first results using the JWST
12:00–1:00 pm ERC 401
On Christmas day 2021, a 10-billion dollar tin can with folded wings and a large wingspan was successfully launched.
6 months later it started releasing pretty pictures. And finding galaxies where they had no business being born.
This Tuesday at a special Astro lunch, several of our department members will report on their first results using the JWST.
Unfortunately, they refused to draw the pretty pictures from JWST on the chalkboard, so we had to allow them to use slides.
[Ok, maybe they did volunteer to draw pictures on the chalkboard. And we hastily arranged for them to use slides instead.] So please join us Tuesday May 2 for a special Tuesday lunch session in ERC 401. We have a packed schedule, come early so we can begin on time.
As usual, pizza will be served. In order to grab a slice, you must be able to draw JWST galaxies on the board better than our speakers. If not, no worries, you will still get some of the crust.
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"Preliminary JWST Results on the Extragalactic Distance Scale"
Wendy Freedman: Overview of the Program (5 min.)
Kayla Owens: First JWST Cepheid Results (15 min.)
In Sung Jang: First JWST TRGB Results (5 min.)
Abby Lee: First JAGB/Carbon Star Results (5 min.)
We will present preliminary results from a long-term program to calibrate the Type Ia supernova (SN Ia) distance scale and improve the accuracy in measurements of the Hubble constant. We have been awarded time in Cycle 1 to measure the distances to 10 nearby SN Ia host galaxies, as well as to the nearby calibrating galaxy NGC 4258, a galaxy that has a geometric distance measurement based on H2O megamasers. We are measuring the distances to these galaxies using three independent methods: Cepheids, the TRGB and JAGB/Carbon stars, all observed simultaneously. We have re-analyzed the SHoES HST archival data, applying strict criteria for the sample selection, and making use of the high-resolution JWST data to eliminate crowded and blended Cepheids. The JWST data have almost 10 times the sensitivity of the HST data and four times the resolution. We have shown that crowding is a significant issue for the Cepheids observed with HST, even for galaxies as close as 20 Mpc. At this point in the program, our results remain blinded. Ultimately, for the Cepheids, we will have an improved measurement of the reddening due to dust, a constraint on the metallicity effect, and lower systematics as a result of crowding. In addition, we will have two independent calibrations from the TRGB and JAGB stars. We expect to have results on Ho within a year. -
Hsiao-Wen Chen and Mandy Chen (20 min)
JWST NIRspec IFU observations to spatially and spectrally resolve quasar feeding and feedback at high redshift. Based on results published in a few papers, https://ui.adsabs.harvard.edu/abs/2022ApJ...940L...7W/abstract https://arxiv.org/abs/2303.06970, and https://arxiv.org/abs/2303.08952. -
Michael Zhang (10 min)
"The First Multi-wavelength Map of an Ultra-short-period sub-Earth"
GJ 367b is tiny (0.633 M_earth, 0.699 R_earth), extremely dense (10 g/cm^3), and whizzes around its star in 0.32 days. Basically, it's a ball of hot iron. But does this tiny sub-Earth have an atmosphere, and if so, what is it made out of? We made a 1D map using the Mid-infrared Instrument to find out.