안녕하십니까.

다음주 월요일(8월 1일) 오후 4:00에 대형망원경사업단에서 주관하는 특별 세미나가 예정되어 있음을 알려드립니다.

연사 : 서혜원 박사 (Gemini/NOIRLab)

장소 : 장영실홀 331-2 및 원격연결

일시 : 8월 1일 (월) 오후 4:00 - 5:00

접속주소 : https://us02web.zoom.us/j/85694725008?pwd=NDQzWGhTbC9VbTFLYmJKWXBCbHVsQT09

제목: A missing black hole population of optically invisible X-ray sources in the early universe

초록:

The recent discovery of a significant cross-correlation signal between the residual cosmic X-ray and infrared backgrounds points towards the possibility of a yet undiscovered population of heavily obscured black holes in the early universe. Here I will present the newly-discovered 62 optically invisible X-ray sources (i.e., without any optical/NIR counterparts) in the COSMOS field, ~60% of which are detected in ALMA 870um continuum observations. For those ALMA-detected sources, we found that the majority are most likely heavily obscured AGNs at z=3-6, or even at higher redshift. Some objects show extremely red infrared colors that cannot be explained by any of known obscured AGN/ULIRG spectra, but consistent with the spectral predictions for a direct collapse black hole model. This is possibly the first population of accreting black holes. JWST Cycle 1 observations (PI:Suh) are scheduled for some of these targets to identify the nature of these sources, which is critical not only to start exploring the heavily obscured population at high redshift but also to provide valuable observational constraints on a hidden phase of a significant growth of supermassive black holes in the early universe. 

진행언어 : 영어

오희영 드림.

Dear all,

On August 1 (Mon) 4:00 pm, there will be special seminar hosted by Center for Large Telescopes of KASI.

Speaker : Dr. Hyewon Suh (Gemini/NOIRLab)

Place : Jang Yeong-sil Hall 331-2 & Online

Schedule : August 1 (Mon) 4:00-5:00 pm 

Access: https://us02web.zoom.us/j/85694725008?pwd=NDQzWGhTbC9VbTFLYmJKWXBCbHVsQT09

Title: A missing black hole population of optically invisible X-ray sources in the early universe

Abstract:

The recent discovery of a significant cross-correlation signal between the residual cosmic X-ray and infrared backgrounds points towards the possibility of a yet undiscovered population of heavily obscured black holes in the early universe. Here I will present the newly-discovered 62 optically invisible X-ray sources (i.e., without any optical/NIR counterparts) in the COSMOS field, ~60% of which are detected in ALMA 870um continuum observations. For those ALMA-detected sources, we found that the majority are most likely heavily obscured AGNs at z=3-6, or even at higher redshift. Some objects show extremely red infrared colors that cannot be explained by any of known obscured AGN/ULIRG spectra, but consistent with the spectral predictions for a direct collapse black hole model. This is possibly the first population of accreting black holes. JWST Cycle 1 observations (PI:Suh) are scheduled for some of these targets to identify the nature of these sources, which is critical not only to start exploring the heavily obscured population at high redshift but also to provide valuable observational constraints on a hidden phase of a significant growth of supermassive black holes in the early universe. 

Language : This talk will be given in English.