Galaxy and AGN Science with CSSOS Linhua Jiang Kavli Institute for - - PowerPoint PPT Presentation

Galaxy and AGN Science with CSSOS

NAOC, Oct 17th, 2017

On behave of the CSSOS galaxy and AGN working groups

Linhua Jiang（江林华）

Kavli Institute for Astronomy and Astrophysics Peking University （北京大学科维理天文与天体物理研究所）

v Outline

§ Introduction § Galaxy and AGN science – general

Ø Galaxy science Ø AGN science

§ Galaxy and AGN science – cases § Summary v Some unique capabilities of CSSOS:

Ø Deep and wide imaging survey with excellent PSF sizes Ø Multiple bands (7 bands!) Ø Slitless spectroscopy over very wide (and deep) fields Ø Repeatedly imaging and spectroscopic observations (especially in the deep fields)

CSSOS Science over Cosmic History

Adopted from Brant Robertson’s slide, based on Madau & Dickinson, ARAA, 52, 412 (2014)

Galaxy Morphology and Environment

Evolution, Clustering Protoclusters SMBHs, AGN, Quasars Reionization

Ø Structural and morphological studies of galaxies

§ Wide and deep imaging data with excellent PSF will allow us to study galaxy structure and morphology at redshift between z=0 to z>7 § Size and morphology evolution of (different types of) galaxies across cosmic time § Environment effects: how size and morphology depend on a variety of environmental parameters § Mergers and interacting systems, and their redshift evolution, etc. § Detailed structural and morphological studies of nearby (low-redshift) galaxies, for example, the formation and evolution of bulges and disks

(Jiang et al. 2011)

4’

29 hr int. with Subaru (z band) 4 hr int. with Keck/DEIMOS

10’’

z ~ 0 galaxy, 1 min int. with SDSS

v Galaxy science in general

Ø Physical properties of galaxies

§ Multi-band (7 band) imaging data (plus slitless spectra) will allow us to derive galaxy properties using methods like SED modeling § Physical properties (color, SFR, mass, age, dust, etc.) and redshift evolution of these properties § Galaxy luminosity function and stellar mass function for different galaxy populations, and their evolution § Galaxy evolution, galaxy density field, bias, galaxy quenching, environmental effect, AGN and SF feedback to galaxy evolution, dark matter halo and galaxy properties, etc § For low-redshift galaxies, high-resolution images will allow us to study galaxy outer disk, stellar halo, stellar stream, etc., and perform pixel- based SEDs to obtain spatially resolved stellar populations, spatially resolved mapping of SFR, etc. § ...

v Galaxy science in general

Ø Line-emitting galaxies (ELGs)

§ Deep and wide slitless spectroscopic observations will be very powerful to search for ELGs, such as Lyα emitters, [OII] emitters, and Hα emitters. We will obtain hundreds of millions of ELGs from CSSOS § Physical properties of ELGs and their redshift evolution § Green pea galaxies, BCDs, metal-poor galaxies, etc. § Owing to their secure redshifts, ELGs are particularly useful for studying galaxy clusters and protoclusters § ...

Ø Other science cases

§ The powerful CSSOS will enable many other galaxy-related scientific

• bjectives (a few examples below)

§ Galaxies and quasars/AGN, galaxy-SMBH co-evolution § High-redshift galaxies and cosmic reionization § Coordinated HI gas survey with FAST § ...

v Galaxy science in general

v AGN-related science

(from XUE Yongquan, AGN working group)

• Host galaxies: properties (color, mass, age, morphology, SFR etc.),

galaxy formation mechanisms, AGN triggering mechanisms, MBH-Mbulge relation, co-evolution of galaxies and SMBHs

• Multiwavelength variability: AGN selection, dependence on AGN properties,

correlated variability, physical origins, radiation mechanisms, peculiar transient events, accretion disk theories

• AGN strong lensing: identification, structure of central emission region,

high-z MBH-sigma relation, faint-end LF, cosmological parameters, properties of foreground objects

• Quasar clustering: measurements, dependence on quasar properties,

halo clustering, relation between BH accretion and environments

• Low-mass BHs: identification, origins of SMBH seeds
• etc.

SMBH and galaxy co-evolution? (provided by Luis Ho)

1) When? 2) How? 3) Evolve?

v Galaxy and AGN science – cases

v Structure evolution and morphology classification

• f galaxies (provided by FAN Lulu)

Strong size evolution revealed by HST

q With CSSOS:

• Origin of Hubble sequence
• Dramatic size evolution of (specially quiescent) galaxies and its

dependence on environment

• Morphologies of active galaxies
• Etc.

v Galaxy number counts (by SHEN Shiyin)

v One of the most fundamental statistical results from the survey v A high precision galaxy number counts statistics in 7 bands

provide constrains on

™ galaxy luminosity function, especially the faint end slope ™ galaxy evolution (cosmic SFH and stellar mass assembly history) ™ Calibration of the milky way dust extinction and extinction curve

(e.g. Li & Shen et al. 2017)

v Probing Dwarf Galaxies with CSSOS (from FANG Taotao)

u Dwarf galaxies: testbeds for galaxy formation

• Missing satellites & too big to fail

problems …

• Why is their star formation so inefficient?
• Does reionization photo-evaporate gas

in the smallest dwarfs?

• Probing the faint end of galaxy

luminosity function

u CSSOS: a very powerful telescope

• Deep survey of dwarfs at the faint-end of

the galaxy luminosity function

• Discovering hostless transients such as

novae and SNe in the local universe (indication of low mass field dwarf galaxies, see right figure)

• Mapping the dwarf populations of the

Milky Way (and nearby galaxies)

Conroy & Bullock (2015)

v Mergers at the low-luminosity end (from ZHAO Yinghe)

§ Dwarf galaxies are more unevolved comparing with

massive ones

§ Construct a large, mass-limited dwarf pair sample with

spectroscopic redshifts for BOTH members

§ We can obtain: § merger rate § star formation properties § Etc.

(Stierwalt et al. 2015)

v Studies of resolved stars in nearby galaxies

(by SHI Yong)

§ Multi-color CMD à SFH § A reasonably large sample

è Measurements of the star formation history in a statistically meaningful sample; understand the formation of galaxies in the local group

Dolphin et al. (2003)

Sextans A CMD

Moffett et al. 2016

Stellar Mass Function by Galaxy Type

Ilbert et al. 2013

Stellar Mass Function by Quiescent and Star-forming

v Stellar Mass Functions for different galaxy population and their evolution (By PENG Yingjie)

v Slitless Observations of LBGs, ELGs, and LAEs (by ZHENG Zhenya)

uHST grism spectra from the GRAPES and PEARS projects uHST ACS/WFC G800L Grism, R~69-131, λ: 0.55-1.05 μm.

u Composite z ~ 5 LBG spectra from GRAPES (Top), and those w/o LyA (Middle) and with LyA (Bottom). [Rhoads et al 2009].

LBG w/o LyA LBG with LyA

• Avg. z~5 LBG

uPEARS ELGs [Pirzkal et al. 2013]

u Flux limit of 1 x 10-17 erg s-1 cm-2, Survey area ~120 arcmin2: Ø 174 Ha (0<z<0.49), Ø 401 OIII (0.10<z<0.90), Ø 167 OII (0.5<z<1.6). u With CSST slitless deep survey, we will get tens of millions of these galaxies

GALEX FUV/NUV grism LAEs

CSSOS can select LAEs from z～1 to 7

uLAEs at z>2 are mainly selected from ground narrowband

• technique. CSSOS will

significantly increase the z>2 LAE with much larger area. uLAEs at 1<z<2 are mainly selected from GALEX grism

• bservation. CSST will be the

most powerful instrument to effectively select LAEs at z~1-2.

uCSST Multi-band Imaging & Slitless observations:

Ø Physical properties (morphology, SFR, mass, dust, age, etc) and redshift evolution of these properties of LAEs at z~1-7. Ø Using millions of LAEs to trace the large-scale structure and BAO.

Ø Bright-end Lyα LF Reionization Bubbles with CSSOS

CSSOS will select luminous LAEs

Ø at 1<z<6: luminous galaxies, AGNs, and Quasars at 5.5<z<7: reionization bubbles

Massive galaxy Proto-clusters and galaxy-IGM interactions at z = 2—6

1 Combined with imaging surveys, such as LSST, HSC, we will survey high redshift porto-clusters from different mass (Fernax to COMA progenitors.)

MAMMOTH protocluster at z=2.3 (LAE overdensity >=15

• n 20 Mpc scale)

2 Combined CSST (redshift info) with DESI surveys (huge Lya forest, CIV, Mg II absorber survey volume), we can study the IGM/galaxy interactions. 3 We will directly probe the extended Lya nebula from 50 kpc — 1 Mpc (comoving), which will construct a unique sample of using extended Lya source to map the IGM emission

Seidel +2010 Cai+2017

ß Final sample of SDSS z~6 quasars (Jiang et al. 2016)

§ It took 15 years to obtain a sample of 52 quasars at z~6 § CSST will easily obtain thousands of them, without follow-up identification

v High-redshift (z≥6) quasars (by myself)

Numbers of quasars predicted for LSST

CSSOS capabilities highly suitable:

Multi-band à effective photometric selection of candidates, and to higher redshift Fine PSF à morphology Large sky coverage à yielding a large sample Spectra à secure identification

Example: “Hanny's Voorwerp” 25 kpc from main galaxy Identified from SDSS gri images: quasar ionization echo ~100,000 years ago

Science driver

Lintott et al. (2009)

• Constraint on AGN active

phase and ionizing history

• Impact of the outflow and star

formation

(From WANG Junfeng)

So far, only ~20 such objects were confirmed. CSST will be a very efficient machine to hunt for this kind of objects!

§ The rare class of Changing-look (CL) AGNs, which change their spectral class with the appearance or disappearance of broad Balmer lines accompanied by large-amplitude changes in the continuum in a time scale of years, challenges the unified model. § The nature of the type transition is important for understanding of the evolution of AGNs. The physical mechanism of the type transition is still under debate. Possible explanations are variable absorption (e.g., Elitzur 2012), variations in accretion rate (Elitzur et

• al. 2014), or tidal disruption event (Merloni et al. 2015).

§ CL AGNs provide perfect cases to study the relation between AGNs and their host galaxies. § Recent discoveries of CL quasars demonstrate that such abrupt transitions can occur in quasars where the black holes are more massive and at higher redshift. § Until now, there are less than 20 known CL quasars. (e.g. LaMassa et al. 2015, Ruan et al. 2016, MacLeod et al. 2016, Runnoe et al. 2016, Gezari et al. 2017).

Summary

Ø CSSOS § Deep and wide imaging survey with excellent PSF sizes à Structural and morphological studies of galaxies § Multi-band (7 bands) imaging data (and slitless spectra) à Various galaxy properties and their redshift evolution § Slitless spectroscopy over very wide (and deep) fields à ELGs, their properties, and their evolution § Repeatedly imaging and spectroscopic observations à Galaxy and AGN variability studies