Absorption line survey toward the Galactic center II

Miwa Goto Max-Planck-Institut fuer Astronomie

Heidelberg, Germany

contribution from Subaru to the exploitation of H3+ in space

Here is my acknowledgement to

B. J. McCall (Univ. of Illinois)T. R. Geballe (Gemini Observatory)T. Oka (Univ. of Chicago)T. Usuda (Subaru Telescope)

Japan Society of Promotion of Science

What is Subaru?

It is a Telescope.

Atop at Mauna Kea in Hawaii

8.2-m primary mirrorthe world largest class

Joined the force of exploitation of H3+ in the ISM since 2000

Honolulu Hil

o

Honolulu

Hilo

MaunaKea

Hilo

London

Subaru Base facility in Hilo

Subaru Telescope

How to get there

What is so special about Subaru and its spectrograph

Usually, these two are conflicting demands in observation.

unlike with CO

H3+ so nasty scattered all over the 3um region

still needs high spectral resolution

Velocity dispersion in interstellar cloud < 10 km/s

3.4 um 4.1 um

Oka Phys. Rev. Lett. 45, 531 (1980)

…it is particularly suited for absorption line survey

Which requires wide wavelength coverage

Subaru/IRCS selling point: wide wavelength coverage

Atmospheric transmission

IRCS(Infrared Camera and Spectrograph

H3+ lines

Subaru/IRCS selling point: wide wavelength coverage

High dispersion

Low dispersion

Survey type observation

2-fold:

- extend the series of lines for one object

- Detect lines in as many object 8-m primary helps

Cross-dispersing spectrograph helps

Is powerful mean of observation when a new field is just open

Absorption line Survey

Brief history

Pre Subaru: 1996; detection in ISM ( If there is H3+ in space? )1998-1999: diffuse cloud enigma widely recognized by community

Subaru I: 2002; metastable state

Subaru II: 2005; R(3, 3)l is ubiquitous in the Galactic center.

Subaru III:

(extension toward wavelength)

(Extension of sources.)

(Tom-sans talk yesterday)

(McCall et al. )

(Oka et al. 2005)

(Geballe & Oka 1996)

2006-; What comes next?

Subaru IIIt is ubiquitous!

R(2,2)l : -

R(2,2)l

R(3,3)l

R(1,0)l+R(1,1)u

R(3,3)l : +R(1,0)l : +

At least in Galactic CenterBut only in the Galactic Center

Dots Line Area

-180 pc

Subaru III: How far the boundary extend?

Where R(3,3)ldisappears?

Trick to increase Absorption line survey Use late type stars. ( we know it is not clean) But See, Can use

it.

R(1,1)

R(1,0)

Thanks!!

B. J. McCall (Univ. of Illinois)T. R. Geballe (Gemini Observatory)T. Oka (Univ. of Chicago)T. Usuda (Subaru Telescope)

Japan Society of Promotion of Science