About the INPA Seminars

All seminars are on Fridays (unless otherwise noted) and start at 12:00 (noon) with a brief presentation of the weekly scientific news. Typically the talks end by 13:00. The seminars take place in Bldg. 50A, room 5132.

The committee members are:

The following Seminar schedule for the Institute for Nuclear and Particle Astrophysics is tentative. The seminar becomes final usually a few days before the Friday of the talk.

If you have questions, comments, suggestions or like to be added to the INPA News mailing list please contact: Erica Hall 510-486-4903

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December 17, 2021 @ 12:00 pm - 1:00 pm

Speaker: Jason Sun (CalTech)

Title: Understanding the Cosmological Evolution of Galaxies with Intensity Mapping 


The intensity mapping (IM) technique has been devised as a powerful tool to investigate the formation/evolution of the large scale structure and galaxies, alternative and complementary to the more traditional means relying on galaxy detection. In the high-redshift universe, in particular, synergies of multiple IM tracers have been widely perceived as a promising way of revealing the connection between the emergence of first stars and galaxies and the reionization, a still mysterious chapter of cosmic history that even the JWST might not fully elucidate. I will present two main themes of my research on applications of the IM technique to understand the cosmological evolution of galaxies. On the experimental side, I will introduce the analysis and forecasting work I led for the Tomographic Ionized-carbon Mapping Experiment (TIME). TIME is a novel imaging spectrometer array recently commissioned that pioneers the quest for measuring large-scale intensity fluctuations of the 158-micron [CII] line emission redshifted from the epoch of reionization, which serves an ideal probe of ongoing cosmic star formation that sources the hydrogen-ionizing radiation background. I will discuss how TIME, with an optimization of survey strategy, can inform us about the reionization on its own and through synergies with other probes like galaxy surveys. I will also discuss challenges and opportunities arising from low-redshift “line interlopers”, namely rotational CO lines at z ≈ 0.5 to 2 for TIME, which require some exquisite cleaning strategy to be removed but at the same time allow a census of the molecular gas content of galaxies near the “cosmic high noon”. On the theory side, I will introduce LIMFAST, a fast, semi-numerical simulation developed to physically and self-consistently simulate a large set of high-redshift line-intensity mapping (LIM) data in different frequency regimes, including tracers of neutral gas (e.g., HI 21cm) and star-forming galaxies (e.g., Lyα, [CII]). I will elaborate on the scientific applications of LIMFAST to simulate multi-tracer LIM observations of high-redshift galaxies and their interplay with the intergalactic medium during reionization. Particular emphases will be on (1) how various LIM signals, such as Hα, Lyα and [CII], and their cross-correlations with the HI 21cm signal, may be affected by the astrophysics governing galaxy formation, such as feedback and star formation laws; and (2) how these astrophysical processes may be studied with future LIM experiments to deepen our understanding of high-redshift galaxy populations from both observational and theoretical perspectives. 
Join Zoom Meeting
Meeting ID: 987 3932 7626


December 17, 2021
12:00 pm - 1:00 pm

INPA guests from campus can now come up to the lab early on Fridays. The INPA Common Room (50-5026) is reserved for our guests from 10:00 am to 12:00 noon, and from 1 pm to 5 pm. Note that the seminars are now held in 50A-5132 to accommodate a larger number of attendees.

Also, on Fridays from 1:00 pm to 2:00 pm you are welcome to join the INPA Speaker for a brown-bag lunch in the small Pers Hall conference room, 54-130B.

INPA Tea Series

The Physics and Nuclear Science Divisions have together been leaders in revolutionary changes in our understanding of neutrinos and cosmology. Everyone is welcome to attend the open forum. Tea and light refreshments will be served.

INPA Common Room (50-5026)
3:30 pm

Access to the Lab

For a shuttle pass please email Erica Hall. Please note: the pass is only valid for the day of the seminar.

If you have questions, comments, or suggestions please contact, preferably via email, Erica Hall.