Subaru Seminars



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The Subaru Seminar is usually held in Room 104 of the Hilo Base Facility, adjacent to the main lobby. Everyone is welcome to attend. If you are interested in giving a seminar, please contact Subaru seminar organizers (Tae-Soo Pyo, Sherry Yeh, Nagayoshi Ohashi) by email : (please change"_at" to @).

May 27, Tuesday, at 11:00 am

" The nature and evolution of star-forming galaxies over the last 11Gyrs with a robust, homogeneous selection "

David Sobral

(IA/CAAUL Lisbon & Leiden Observatory)

I will present the results from the deepest and widest narrow-band surveys ever undertaken with the best 4-8 m telescopes (CFHT, UKIRT, Subaru and the VLT); a unique combined effort to select large, robust samples of (mostly) H-alpha (Ha) star-forming galaxies at z=0.20, 0.40, 0.8, 0.84, 1.47 and 2.23 (corresponding to look-back times of 2, 4.2, 7.0, 9.2 and 10.6 Gyrs) in a uniform manner over ~2-10 deg^2 in the COSMOS, UDS and SA22 fields. Our results reveal the exponential decline of the typical star-formation rate of galaxies (SFR*) over the last 11 billion years, and very little evolution in the stellar mass function of star-forming galaxies, with strong implications to the main drivers of galaxy evolution. Our Ha star formation history also implies a stellar mass density growth which is in perfect agreement with independent observations of the stellar mass density growth over the last 11 billion years, finally resolving the worrying disagreement seen in the literature. Finally, I will show how our large and homogeneously selected samples of Ha emitters across cosmic time are also being used to measure and understand the evolution of star-forming galaxies in the last 11 Gyrs, by conducting detailed resolved dynamics (e.g. SINFONI, KMOS), dust (e.g. ALMA, Herschel, Spitzer), clustering, environment, and (resolved) metallicity studies (e.g. KMOS, FMOS).

" The first 3 Gyrs with multiple large, well calibrated Lya surveys "

Jorryt Matthee

(Leiden Observatory)

I will present the first results from the CF-HiZELS survey, which is a large area, medium depth (22.2 AB) near infrared narrow-band survey covering 10 square degrees in part of the SSA22 field with the Canada-France-Hawaii Telescope. I will present how we used these observations to obtain the largest samples of high redshift emission line galaxies to date, such as ~3500 star-forming H-alpha emitters at z=0.8 and ~900 [OII] emitters at z=2.2. These samples are now being used for unique studies of resolved dynamics and metallicities with new instruments as KMOS. The main focus is on how we searched for Lyman alpha candidates at z=8.8 by applying a set of stringent criteria on our sample of line-emitters. I will show how to distinguish z=8.8 galaxy candidates from lower redshift interlopers, how including line-emission improves photometric redshift constraints and I will present the most plausible Lya at z=8.8 candidates to date and the spectroscopic follow-up with the SINFONI instrument on the VLT. I will shortly discuss the results, which have strong implications for existing samples of very high redshift LAE candidates and for ongoing and future surveys. I will conclude with our future plans on how we will improve the understanding of the Lya emission line at high redshift using a wide variety of surveys.

Seminars are also held at JAC, CFHT, and IfA.

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