environmental processing of galaxies in the filaments...

Environmental Processing of Galaxies in the Filaments around the Virgo Cluster

Hyein Yoon ( 혜인 윤 )

Yonsei University

Aeree Chung (Yonsei), Chandreyee Sengupta (KASI), O. Ivy Wong (ICRAR/UWA), Martin Bureau (Oxford), Soo-Chang Rey (CNU), Jacqueline van Gorkom (Columbia)

Asia-Pacific Regional Workshop on HI Science November 2-4, 2015

In the Cluster Environment

•  Galaxies are actively interacting with their surroundings within the cluster.

ICM-ISM Interaction (e.g. NGC 4522)

Gravitational Interaction (e.g. NGC 4567+4568)

2

Gravitational Interaction

ICM-ISM Interaction

(Past) ICM-ISM Interaction

Distance from M87 (Mpc)

Chung et al. (2009)

Yoon et al. (in prep.) Optical Optical + HI (contour)

Optical Optical + HI (contour)

In the Outskirts of the Cluster

•  Galaxies may already get affected by their surroundings before they arrive in the core of the cluster.

3

Gravitational Interaction ICM-ISM Interaction ICM-ISM Interaction (early) ICM-ISM Interaction (past) Possible Gas accretion

R.A. (2000) Chung et al. (2009)

Yoon et al. (in prep.)

Optical + HI (contour) Optical + HI (contour)

NGC 4808 DHI/DB = 2.84 def HI = - 0.58

NGC 4713 DHI/DB = 3.15 def HI = - 0.31

Distance from the cluster center Frac

tion

of H

I-poo

r gal

axie

s

DEC

. (20

00)

Solanes et al. (2001)

Color: Key process(es) on the Virgo spirals (Background : Virgo X-ray; Böhringer et al. 1994)

“Pre-processing” of Galaxies

•  Galaxies can be “pre-processed” before they falling into a massive cluster. •  Environmentally driven evolution occurs in lower density environments.

4

McGee et al. (2009) Hou et al. (2014)

HI Imaging of Galaxies in Virgo Outskirts

•  To find observational evidence of “pre-processing”, we are carrying out HI imaging study of 14 spirals in the filaments around the Virgo cluster.

•  Key questions:

–  Can we find any evidence that infalling galaxies are interacting with the gas filaments?

–  What kinds of gas-gas interaction can take place due to the gas in the filaments? (e.g. Gas accretion or Gas stripping?)

–  How will “pre-processing” affect galaxy evolution within the cluster?

5

HI Galaxies around Virgo

6

DEC

. (20

00)

R.A. (2000)

Virgo Cluster cz [

km s

-1 ]

Color: radial velocity (cz) Size: HI gas masses (based on ALFALFA, HIPASS, LEDA)


7R.A. (2000)

DEC

. (20

00)

Virgo

Color: radial velocity (cz) Size: HI gas mass (ALFALFA/HIPASS/LEDA)

Three Filamentary Structures around Virgo


Phase-Space View of the Filaments

8

M49

M87

M86

A

B

E

S

W

N

M

Virgo

NW filament (connected to group M, group W)

NE filament (infalling from the backside of group A)

Gavazzi et al. 1999

Distance from the cluster center Southern extension (connected to group S)

|Δv|

/ σ


Mapping the 3D structure of Virgo cluster filaments with Tully-Fisher Distances (è see Kyle’s poster)

9R.A. (2000)

DEC

. (20

00)

Virgo

Color: radial velocity (cz) Size: HI gas mass (ALFALFA/HIPASS/LEDA)

HI Observations

VirgoCluster

VirgoCluster

VirgoCluster

R.A. (2000)

DE

C. (

2000

) D

EC

. (20

00)

NGC 5116

VirgoCluster

VirgoCluster

VirgoCluster

R.A. (2000)

DE

C. (

2000

) D

EC

. (20

00)

NGC 5116

VirgoCluster

VirgoCluster

VirgoCluster

R.A. (2000)

DE

C. (

2000

) D

EC

. (20

00)

NGC 5116

Telescope (array)

Obs. date

Int. time (hr)

BW (MHz)

# of Chan.

NE VLA

(D-array) (CASA)

July Aug 2014

1.5 x 5 ~ 8 hrs

16.00 (~ 3400 km/s)

512 (1 chan ~ 7 km/s)

NW WSRT (72m)

(MIRIAD)

Dec 2013 / Jan Apr May

July Aug 2014

12 x 5 + 18 x 2 ~ 96 hrs

20.00 (~ 4300 km/s)

1024 (1 chan ~ 4 km/s)

SE GMRT (AIPS) Jan 2014

10 x 2 ~ 20 hrs

16.67 (~ 3400km/s)

512 (1 chan ~ 7 km/s)

NE Filament (JVLA)

SE Infalling Group (GMRT)

NW Filament (WSRT)

1. Gas-rich Galaxies è Gas Accretion?

10

R.A. (2000) R.A. (2000) R.A. (2000)

MCG-01-33-059 (GMRT) SE Infalling Group

UGC 07039 (WSRT) NW filament

NGC 5089 (JVLA) NE filament

(Last contour level: 3.4 x 1019 cm -2)

•  DHI/Dopt = ~ 3.80 •  HI deficiency = - 0.61 •  Log (HI mass-to-light) = - 0.01

(Last contour level: 4.0 x 1019 cm -2) (Last contour level: 6.1 x 1019 cm -2)

•  DHI/Dopt = ~ 3.10 •  HI deficiency = - 0.84 •  Log (HI mass-to-light) = 0.20

•  DHI/Dopt = ~ 5.50 •  HI deficiency = - 0.59 •  Log (HI mass-to-light) = - 0.26

Gas-rich Galaxies è Gas Accretion?

10

R.A. (2000)

DEC

. (20

00)

R.A. (2000) R.A. (2000)





•  DHI/Dopt = ~ 3.80 •  HI deficiency = - 0.61 •  Log (mass-to-light) = - 0.01


•  DHI/Dopt = ~ 3.10 •  HI deficiency = - 0.84 •  Log (mass-to-light) = 0.20


Gas-rich Galaxies è Gas Accretion?

10

R.A. (2000)

DEC

. (20

00)

R.A. (2000) R.A. (2000)







•  DHI/Dopt = ~ 3.10 •  HI deficiency = - 0.84 •  Log (mass-to-light) = 0.20


DEC

. (20

00)

Optical + HI (contour)

1. Gas-rich Galaxies è Gas Accretion?

11

VirgoCluster

VirgoCluster

VirgoCluster

R.A. (2000)

DE

C. (

2000

) D

EC

. (20

00)

NGC 5116

Roberts & Haynes (1994)


NW Filament (WSRT)

2. Gas-poor Galaxies è Gas Stripping?

12

IC 3908 (GMRT) SE Infalling Group



•  DHI/Dopt = ~ 1.50 •  HI deficiency = 0.04 •  Log (HI mass-to-light) = - 0.74

•  DHI/Dopt = ~ 1.80 •  HI deficiency = 0.15 •  Log (HI mass-to-light) = - 1.01


2. Gas-poor Galaxies è Gas Stripping?

13Roberts & Haynes (1994)


3. Interacting Galaxies with Close Companions

14



UGC 07143 (WSRT) – Right NW filament

PGC 038859 (WSRT) - Left NW filament

•  Sc •  DHI/Dopt = ~ 3.84 •  HI deficiency = - 0.55 •  Log (HI mass-to-light) = - 0.35 •  Neighbor = SDSS J120958.86+250106.3

•  SBcd •  DHI/Dopt = ~ 7.90 •  HI deficiency = - 0.63 •  Log (HI mass-to-light) = - 0.21 •  Neighbor = NGC 4158


Summary and Future Work

•  We are carrying out HI imaging study of galaxies, selected from three filamentary structures around the Virgo cluster.

•  Our sample are potentially interacting with their surroundings. We found some galaxies show morphological peculiarities in HI: è Gas accretion, Gas stripping, Interacting with close companions.

•  To understand details of the process(es), further kinematical analysis of the sample is required. Also, we will examine complementary multi-wavelength data to probe various mechanisms of pre-processing.

•  Great sensitivities of SKA will enable us to obtain high resolution HI images of pre-processed galaxies even in distant universe.

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environmental processing of galaxies in the filaments...

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