SUMMARY OF PROPOSAL 61021

MR KATSUJI KOYAMA
KOYAMA@CR.SCPHYS.KYOTO-U.AC.JP

KYOTO UNIV.
KYOTO JAPAN 606-01
KYOTO
KITASHIRAKAWA-OIWAKE-CHO, SAKYO
Tel: 075-753-3833 Fax: 075-701-5377
Medium: 2.5GB8MM
Subject: STARS

X-RAYS FROM YOUNG PROTOSTARS


ABSTRACT

Several observations with ASCA and ROSAT have shown that protostars are emitting X-rays, sometimes at very high levels (Lx ~ 10^32 - 36 erg s-1), either steadily or during flares. However, the detected protostars are relatively evolved (Class I), with ages ~ 10^5 yrs. We want to investigate whether younger protostars (Class 0), with ages ~ 10^4 yrs, are also X-ray emitters. The detection of X-rays from low-mass protostars has major implications on early stages of evolution of stars and the solar nebula. The main difficulty arises from the high extinction (Av > 70 mag) of these objects, but ASCA is well suited to overcome this difficulty with the extended energy range. We propose deep exposures (50 ks) of two star-forming regions with Class 0 sources, never observed so far in X-rays.

CO-INVESTIGATORS
CO-I NAME INSTITUTE COUNTRY
YOHKO TSUBOIKYOTO UNIV.JAPAN
THIERRY MONTMERLESACLAYFRANCE
NICOLAS GROSSOSACLAYFRANCE
ANDR'E PHSACLAYFRANCE
ERIC FEIGELSONPEN STATE UNIV.USA

TARGETS

TARGET NAMEPRIRADECTIMETCOFFGISSIS CNTOBS
1)L1448
1
51.4017 30.7557 50 ksN
Y
P
0.20000
1
2)L1582B
1
83.0783 12.8186 50 ksN
Y
P
0.20000
1