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HI Observations of in the Filaments/Groups around Hyein Yoon (윤혜인; Yonsei University)

MCG-01-33-059 (GMRT) NGC 5116 (JVLA) UGC 07143 (WSRT)

HI (contour) + Optical

Aeree Chung (Yonsei), Chandreyee Sengupta (Yonsei), Jacqueline van Gorkom (Columbia), Martin Bureau (Oxford), O. Ivy Wong (ICRAR/UWA), Shan Huang (NYU), Soo-Chang Rey (CNU) 2018 Radio Telescope User’s Meeting (KASI) Environmental Processes in Clusters Interactions between galaxies and their surroundings in clusters

Gravitational Interactions ICM-ISM Interactions § Galaxy-Galaxy interaction § stripping (Mihos 2004) (Gunn & Gott 1972) § Galaxy harassment § Thermal evaporation (Moore et al. 1996) (Cowie & Songaila 1977) § Galaxy-Cluster interaction § Turbulent-viscous stripping (Byrd & Valtonen 1990, Bekki 1999) (Nulsen 1982)

Galaxy-Galaxy interaction NGC 4567 Ram-pressure stripping NGC 4522 (Credit : C. Mihos, and C. McBride) NGC 4568 (Credit : B. Vollmer) (Chung+ 2009) (Chung+ 2009)

2 Environmental Processes in Galaxy Clusters Interactions between galaxies and their surroundings in clusters (e.g. ICM-ISM interactions within R200 of Virgo)

VIVA II project 48 spiral galaxies located throughout the (VIVA I: Chung+2009)

High resolution HI data (VLA) + Impact of local environments ➔ 35 galaxies have signs of “Gas stripping” ICM-ISM interactions: - Early stage (Yoon+ 2017) - Active stage - Past stage - Slow process

3 Environmental Processes in Galaxy Clusters Interactions between galaxies and their surroundings in clusters (e.g. ICM-ISM interactions within R200 of Virgo) Early stage of N4396 VIVA II project gas stripping

stellar disk Optical + HI (contour)

Most active gas stripping

N4522 ICM-ISM interactions: Gas stripped - Early stage - Active stage in the past - Past stage - Slow process N4405 4 Chung+ 2009 Environmental Processes in the Outskirts of Clusters Galaxies may already get affected by their surroundings before they arrive in the core of the cluster (“Pre-processing”)

VIVA II project

ICM-ISM interactions: - Early stage - Active stage - Past stage - Slow process

5 Environmental Processes in the Outskirts of Clusters Galaxies may already get affected by their surroundings before they arrive in the core of the cluster (“Pre-processing”)

VIVA II project Gas stripping? N4698

stellar disk

Optical + HI (contour)

Gas accretion? N4808

ICM-ISM interactions: - Early stage - Active stage Chung+ 2009 - Past stage - Slow process

6 N4405 “Pre-processing” of Galaxies in the Outskirts of Clusters Galaxies may already get affected by their surroundings before they arrive in the core of the cluster (“Pre-processing”)

Solanes+ 2001 ← A good fraction of HI-deficient galaxies in cluster outskirts poor galaxies - Fraction of Recent studies on pre-processing: gas 1.5 • Low HI detections (processed HI) 1.0 in group environments (Mhalo 0.5 dependence) - Hess and Wilcots 2013 0.0 • Gas-poor and red galaxies HI deficiency HI in infalling regions of Abell 963 - 0.5 0 1 2 3 4 5 - BUDHIES II: Jaffé+ 2015 r / RABELL • Lower formation rate in groups/filaments around Coma supercluster - Cybulski+ 2014 7 HI Imaging Study of Galaxies in Virgo Filaments/Groups

Key Questions:

§ Can we detect any observational evidence on gas morphologies that galaxies be “pre-processed” in low-density environments?

§ What kinds of physical processes can take place in infalling structures? (e.g. Gas accretion or Gas stripping + Tidal interactions)

§ How does the pre-processing during the infalling would enhance the galaxy evolution within the cluster?

To answer the above questions: High resolution HI imaging study of 14 late-type galaxies in the filaments/groups around the Virgo cluster

8 HI Detections (Single HI Detections dish) in Virgo Filaments/Groups - - - gas HI Size: Color: ( LEDA (inhomogeneous) HIPASS (Parkes) ALFALFA (Arecibo) mass (single dish) DEC. (2000) cz ) R.A. (2000) R.A. Virgo

cz [ km s-1 ] 9 HI Observations of Galaxies in Virgo Filaments/Groups NE Filament NW Filament (sheet-like) JVLA WSRT (D) (72m)

NGC 5116 cz [km/s]cz

NGC 5116 [km/s]cz NGC 5116 DEC.(2000) DEC.(2000)

Virgo DEC.(2000) Virgo Virgo GMRTCluster Virgo Virgo 3 gas-poor Cluster Cluster Virgo DEC. (2000) DEC. Cluster Cluster 2 gas-rich ~ 124 hours ~ 3-5 x 1019 cm-2 7 gas-rich SE Infalling Virgo Int. R.A. (2000) Virgo Telescope Obs. time BW # of Group (array) date Virgo (MHz) Chan. Cluster (hr) Cluster Cluster VLA July Aug 1.5 x 5 NE (D-array) 16.00 512 (CASA) 2014 ~ 8 hrs (~ 3400 km/s) (1 chan ~ 7 km/s) 12 x 5 WSRT Dec 2013 / 20.00 1024 DEC.(2000) NW (72m) Jan Apr May + 18 x 2 DEC.(2000) (~ 4300 km/s) (1 chan ~ 4 km/s) (MIRIAD)DEC.(2000) July Aug 2014 1 gas-poor ~ 96 hrs 10 x 2 512 1 gas-poor SE GMRT Jan 2014 16.67 (AIPS) ~ 20 hrs (~ 3400km/s) (1 chan ~ 7 km/s)10 R.A.R.A. (2000) (2000) R.A. (2000) R.A. (2000) HI Imaging: Gas-richer Galaxies ➔ Gas Accretion?

MCG-01-33-059 (GMRT) • Very extended and SE infalling group asymmetric gas disk • High gas content • Distorted velocity field and warp • No obvious neighbors D ~ 1.5’ • Star forming regions Optical P-V diagram

HI (blue, GMRT) Optical (red, DSS) Optical Hα (green, OHP) along (Lowest HI contour level: 3.4 x 1019 cm -2) minor mom 1 • DHI/Dopt ~ 3.80 • def HI ~ - 0.61

• log (MHI/LB) = - 0.01 GALEX 11 HI Imaging: Gas-richer Galaxies ➔ Gas Accretion?

MCG-01-33-059 (GMRT) DHI/Dopt ~ 3.8 UGC 07039 (WSRT) DHI/Dopt ~ 3.1 SE Infalling Group def HI ~ -0.61 NW filament def HI ~ -0.84

Optical mom 1 + HI (contour)

(Lowest HI contour level: 3.4 x 1019 cm -2) (Lowest HI contour level: 4.0 x 1019 cm -2)

IC 0777 (WSRT) DHI/Dopt ~ 2.5 NGC 4152 (WSRT) DHI/Dopt ~ 2.0 NW filament def HI ~ -0.70 NW filament def HI ~ -0.66

(Lowest HI contour level: 5.4 x 1019 cm -2) (Lowest HI contour level: 5.0 x 1019 cm -2) 12 HI Content: Gas-richer Galaxies ➔ Gas Accretion?

def HI vs Clustocentric distance 1.5

1.0 log (MHI/M*) vs log M* 0.5 U7186

HI deficiency HI 0.0

P1760270 )

-0.5 * U7039 0 1 2 3 4 5 /M r / RABELL HI P38859 U7143

Solanes+ 2001 M

( IC777 og > N4152

0 l B /L

HI -1

along major

mom 1 (Lowest HI contour level: 3.5 x 1019 cm -2)

• DHI/Dopt = ~ 1.50 • def HI ~ 0.04 14 • log (MHI/LB) ~ - 0.74 HI Imaging: Gas-poorer Galaxies ➔ Gas Stripping?

IC 3908 (GMRT) DHI/Dopt ~ 1.50 SE infalling group def HI ~ 0.04

(Lowest HI contour level: 3.5 x 1019 cm -2)

NGC 5116 (JVLA) DHI/Dopt ~ 1.80 NE filament def HI ~ 0.15

(Lowest HI contour level: 6.1 x 1019 cm -2) 15 HI Imaging: Gas-poorer Galaxies ➔ Gas Stripping? D /D ~ 1.50 IC 3908 (GMRT) HI opt Similar to Virgo galaxies SE infalling group def HI ~ 0.04 in the early stage of gas stripping one truncation, (no - sided extension) sided

(Lowest HI contour level: 3.5 x 1019 cm -2)

NGC 5116 (JVLA) DHI/Dopt ~ 1.80 NE filament def HI ~ 0.15

(Lowest HI contour level: 6.1 x 1019 cm -2) DHI/DB 16 HI Content: Gas-poorer Galaxies ➔ Gas Stripping?

def HI vs Clustocentric distance 1.5

1.0 NGC 5240 log (MHI/M*) vs log M* 0.5 UGC 08662

HI deficiency HI 0.0 )

-0.5 *

0 1 2 3 4 5 /M HI U8662 Solanes+ 2001 r / RABELL M ( N5116 og >

0 l B N5240 /L

HI -1

UGC 07143 (WSRT) Optical – right; NW filament

• DHI/Dopt ~ 3.84 • def HI = - 0.55 d ~ 13 kpc • Close neighbor (left): Δv ~ 17 km/s SDSS J120958.86+250106.3

(Lowest contour level: 6.3 x 1019 cm -2)

PGC 038859 (WSRT) - left; NW filament

• DHI/Dopt ~ 7.90 • def HI ~ - 0.63 • Close neighbor (right): NGC 4158 (Lowest contour level: d ~ 70 kpc 3.1 x 1019 cm -2) Δv ~ 20 km/s 18 Extended Study: and HI Gas in Virgo Field

1. Mapping the star formation and HI gas properties in three Virgo filaments and two groups è NUV-r, W3-W1, g-r colors and HI content

color: NUV - r size: stellar mass

Voronoi 2. Statistical analysis with all galaxies in Virgo field (1800 < cz < 3300 km/s)

NUV-r vs log M* log(MHI/M*) vs log M*

MST Cluster Group Filament Void

19 Yoon+ in prep Summary

• We carried out 124 hours HI observations by using the GMRT, JVLA and WSRT to find observational signatures of environmental processes in Virgo filaments/groups. • Our galaxies show intriguing morphological peculiarities in HI, suggesting “pre-processing” in the low-density environments. è - Gas accretion: extended gas-rich disk, asymmetry in velocity field - Gas stripping: one-sided tail (early stage), no truncations - Interacting pairs • In addition, we mapped the stellar and gas properties of galaxies in large-scale environments around Virgo field. è Non-negligible numbers of red and gas-poor galaxies in the filaments and groups are found, suggesting that cool gas can be removed before falling to the cluster. 20 Lessons and Challenges • Sensitivity: • This study to detect faint signatures of pre-processing in HI by using various arrays can be a good pilot study to get deeper with the SKA1-MID. • SKA1 is expected to reach a 5σ N(HI) sensitivity of 6×1018 cm-2 (at 30” resolution, 20 km/s width, in a 10 hours-integration; de Blok+ 2014). • Visualization: • The most important thing of the HI imaging is to visualize diffuse and faint signatures of the galaxies, however, it is still hard to entirely rely on the pipelined dataset to obtain the best images. • Together with the huge data volume and transfer issues, automatic deconvolution tools for resolved structures is also necessary. • Processing tools: • The data has been processed by different processing programs (GMRT - AIPS, WSRT - MIRIAD, JVLA - CASA, Final imaging - AIPS). • Each has strengths and weaknesses, and hence it should be considered to develop the upcoming platforms for future facilities. 21