UV/Optical/IR Observations

Jiangtao Li has been actively involved in UV/optical/IR observations of the high-redshift Universe, local galaxies, and supernova remnants. He is leading or participating many space- and ground-based observations in the corresponding band, using HST, SOFIA, Magellan, MDM, Gemini, Palorma 200-inch etc. He is also involved in the study of early science of future telescopes. In particular, he is developing commissioning phase projects for Magellan/IFUM, and is a member of the University of Michigan ELT/HARMONI and MOSAIC science groups.

Below I only summarize the UV/Optical/IR projects I'm leading or actively involved in now. These only include priority data, while archival data used in the study are not listed (there are quite a lot especially from the CHANG-ES consortium). For other multi-wavelength projects related to the same science, please refer to my CV for details.

For a brief summary, in recent years in the field of UV/Optical/IR observations, Jiangtao Li has obtained 15 nights of Magellan, more than 60 nights of MDM Observatory telescopes, 3 hrs of SOFIA time as PI, as well as about 10 nights of Gemini, 0.5 nights of Palorma 200-inch, 17 orbits of HST, and an archival HST program as co-I.

High-Redshift Universe

Identification of Quasars at the EoR and Cosmic Dawn

Key science:

Identify quasars at high-z, typically at z>6.

Key collaborators:

Xiaohui Fan (U Arizona); Feige Wang (U Arizona); Jinyi Yang (U Arizona)

Major facilities and the allocated time:

Until now, in total 8.5 nights of Magellan time as PI and 3 nights as co-I, 33.3 hours + 6.15 nights of Gemini time as co-I.

Magellan/FIRE:

2016A, 2 nights as PI; 2016B, 1.5 nights as PI; 2017A, 2 nights as PI; 2018A, 3 nights as PI and 3 nights as co-I.

Gemini:

2018A, 33.3 hours as co-I; 2019A, 3 classical nights as co-I; 2019B, 3.15 classical nights as co-I.

High-resolution Spectroscopy of Quasars at High-z

Key science:

1. Study the cool and warm absorbers in the CGM/IGM at high-z, especially the CIV absorbers at the He II reionzation stage, via absorption lines in the high-resolution spectrum of the brightest quasars at high-z.

2. Another science based on this project is to study quasar outflows.

Key collaborators:

Xiaodi Yu (graduate student jointly supervised by me and Prof. Taotao Fang at Xiamen University); Zhijie Qu (University of Michigan); Taotao Fang (Xiamen University)

Major facilities and the allocated time:

Until now, in total 4.5 nights of Magellan time as PI.

Magellan/MIKE:

2019A, 1 night as PI; 2019B, 1.5 night as PI; 2020A, 1 night as PI; 2020B, 1 night as PI.

Emission Line Study of the CGM/IGM at High-z

Key science:

UV emission line nebula around bright quasars, as well as other related science such as high-z galaxies and proto-clusters.

Key collaborators:

Qiong Li (currently a graduate student at Peking University, will start working with me as a postdoc at the University of Michigan in late 2020 or early 2021); Zheng Cai (Tsinghua University); Ran Wang (Peking University); Feige Wang (U of Arizona)

Major facilities and the allocated time:

We have not yet obtained too much time in this field (1 night of Magellan time as PI; 17 orbits of HST time as co-I). Most of our existing works are based on some unapproved HST proposals. But in the near future, study CGM/IGM at high-z with IFUM will be one of my major research field.

Magellan/IFUM:

Commissioning phase proposal submitted, but the first light of this instrument has been postponed to 2021A.

HST:

Cycle 28, 17 orbits as co-I.

Magellan/IMACS:

2019A, 1 night as PI

Local Galaxies

Emission Line Imaging and Spectroscopy Study of the Extraplanar Diffuse Ionized Gas (eDIG) around Local Galaxies

Key science:

Both imaging and spectroscopy observations of optical emission lines around nearby galaxies. In particular, the multislit mask recently designed by me for OSMOS on the MDM 2.4m telescope will greatly increase the efficiency in imaging spectroscopy observations.

Key collaborators:

Liyuan Lu (graduate student jointly supervised by me and Prof. Taotao Fang at Xiamen University); Wei Sun (visiting postdoc at the University of Michigan jointly supervised by me and Prof. Li Ji at the Purple Mountain Observatory); Li Ji (Purple Mountain Observatory); Taotao Fang (Xiamen University); the CHANG-ES consortium.

Major facilities and the allocated time:

Until now, in total 42 nights of MDM 2.4m time as PI; 5 nights of MDM 1.3m time as PI; 3 hrs of SOFIA time as PI; 0.5 nights of P200/CWI time as co-I.

MDM 2.4m:

2016A, 2 nights as PI; 2017B, 6 nights as PI (this is a project studying warm molecular gas using TIFKAM, which is not taken due to instrument problems); 2018A, 3 nights as PI; 2018B, 4 nights as PI; 2019A, 8 nights as PI; 2019B, 7 nights as PI; 2020A, 7 nights as PI; 2020B, 5 nights as PI.

MDM 1.3m:

2018A, 5 nights as PI

SOFIA:

Cycle 5, 3 hrs as PI

Palomar 200-inch/CWI:

2020A, 0.5 nights as co-I

Absorption Line Study of the CGM/IGM around the Milky Way and Other Local Galaxies

Key science:

UV absorption line study of the CGM around local galaxies.

Key collaborators:

Zhijie Qu (University of Michigan); Joel Bregman (University of Michigan); Bart Wakker (University of Wisconsin); Yuming Fu (Peking University); Xue-Bing Wu (Peking University)

Major facilities and the allocated time:

We haven't obtained much time in this field yet (8 nights of MDM 2.4m time as PI; 1 night of Magellan time as PI; an HST cycle 27 archival program as co-I), except for some preliminary search of candidate background quasars (12 nights of MDM 1.3m time as PI). Most of our projects are based on a few unapproved HST proposals.

HST:

Cycle 27 archival project, co-I

MDM 2.4m:

2015A, 4 nights as PI; 2015B, 4 nights as PI

MDM 1.3m:

2020A, 7 nights as PI; 2020B, 5 nights as PI

Magellan/IMACS:

2015B, 1 night as PI

Globular Cluster System in Nearby Massive Spiral Galaxies

Key science:

Galaxy archeology based on globular clusters in the most massive spiral galaxies.

Key collaborators:

Hui Li (MIT); Oleg Gnedin (University of Michigan); William Harris (McMaster University)

Major facilities and the allocated time:

This is just an unapproved HST proposal, plus some theoretical works.

Supernova Remnants

Imaging Spectroscopy of Galactic Supernova Remnants

Key science:

2D imaging spectroscopy of optical emission lines studying the interaction between supernova remnants and the ISM.

Key collaborators:

Liyuan Lu (graduate student jointly supervised by me and Prof. Taotao Fang at Xiamen University); Wei Sun (visiting postdoc at the University of Michigan jointly supervised by me and Prof. Li Ji at the Purple Mountain Observatory)

Major facilities and the allocated time:

We do not have separated proposals on this project. All the observations, including both narrow-band imaging observations and the 2D imaging spectroscopy observations based on the newly designed multislit mask for OSMOS on MDM 2.4m, are taken during other observations in order to fill the gap when the objects are not visible. Please see other MDM 2.4m observations for details.

Right now I'm just writing softwares to reduce data for this new observation mode, with the help from two students. When it is finished, we will start a survey of large bright Galactic SNRs, and more collaborators will be added.

Future Facilities and Related Science

Jiangtao Li has also been highly involved in planning the science with some future facilities. These mostly include the University of Michigan facilities (Magellan and ELT), while we are also preparing proposals with collaborators for some large missions open to the entire astronomy community (e.g., JWST).

Magellan/IFUM

IFUM is the new IFU for the 6.5m Magellan/Clay telescope developed by Prof. Mario Mateo at the University of Michigan. It has a variaty of configurations with different angular resolution, FOV, spectral resolution, and covering different wavelength range. The major project Jiangtao Li will lead, largely in collaboration with the new postdoc Qiong Li, and probably the new faculty member Sean Johnson at the University of Michigan, will be studying the UV emission line nebula at high-z. In particular, the broad wavelength coverage of IFUM with the low resolution mode is unique compared to other similar facilities such as KCWI on Keck and MUSE on VLT, and will allow us to simultaneously cover UV emission lines from OVI to CIV at a certain redshift range.

ELT (HARMONI, METIS, MOSAIC, HIRES)

University of Michigan has joined four instruments of the ELT, two first light (HARMONI and METIS), and two second light (MOSAIC and HIRES). Compared to Magellan, HARMONI is similar as IFUM, METIS is more or less similar as FIRE, MOSAIC is a combination of IFUM and M2FS, while HIRES is similar as MIKE. Therefore, you may expect what could we do with these ELT instruments. Jiangtao Li has been put into the HARMONI and MOSAIC group for early science study, while he will also be interested in using other instruments to conduct his research.

JWST and Others

We are preparing proposals for JWST Cycle 1, mainly in two fields, local galaxies and high-z Universe. Due to COVID-19, there are quite a lot of uncertainties on the schedule of JWST. We will keep our eyes on the status.

There are more to be added ......