[Message Prev][Message Next][Thread Prev][Thread Next][Message Index][Thread Index]

[vsolj-alert 67] CI CAM =? XTEJ0421+560

CI CAM =? XTEJ0421+560

　Ｘ線新星 XTE J0421+560 が CI Cam と同一であることはほぼ間違いないようで
　す。９等にアウトバーストしていることが確認されています（ちょっと向けて
　みれば一発で見える明るさですね！）

　予想通り、VLAで電波観測が行われてその結果がCI Camの位置に一致していまし
　た。He IIの輝線も予想通り検出されています。
　光学観測の可能性のあった晩の日本の天気が良くなかったのは残念でした。

　おそらく我々の相当近くに位置している高いエネルギートランジェント天体で
　しょう。今後の詳細な観測が期待されます。

　詳しくは IAUC 6857 をご覧ください。

Subject: [vsnet-alert 1632] Forward: CI CAM =? XTEJ0421+560 Optical spectroscopy and photometry (Garcia)

Date: Fri, 3 Apr 1998 17:21:02 -0500
From: garcia@cfa219.harvard.edu (Mike Garcia)
Message-ID: <vsolj-alert67@hoge.baba.hajime.jp>
To: BAILYN@astro.yale.edu, ajct@laeff.esa.es, chaswell@star.maps.susx.ac.uk,
        e.kuulkers1@physics.oxford.ac.uk, fghigo@nrao.edu,
        garcia@head-cfa.harvard.edu, guy@mrao.cam.ac.uk,
        ewaltman@rsd.nrl.navy.mil, jem@head-cfa.harvard.edu,
        lewin@space.mit.edu, marshall@milkyway.gsfc.nasa.gov,
        pac@astro.ox.ac.uk, rhjellmi@aoc.nrao.edu, rmw@lowell.Lowell.Edu,
        rpf@astro.uva.nl, rr@space.mit.edu, shrader@grossc.gsfc.nasa.gov,
        starrfie@hydro.la.asu.edu, stroh@pcasun1.gsfc.nasa.gov,
        swank@pcasun1.gsfc.nasa.gov, takeshim@ginpo.gsfc.nasa.gov,
        tavani@astro.columbia.edu, narayan@cfa.harvard.edu,
        vsnet-alert@kusastro.kyoto-u.ac.jp
Subject: [vsnet-alert 0] CI CAM =? XTEJ0421+560 Optical spectroscopy and photometry

Dear Colleagues: 
	Attached is the text of our submittion to the IAUC.
Good luck observing tonight!  

--------------


M.R. Garcia, P. Berlind, E. Barton, J.E. McClintock (Center for
Astrophysics), P.J. Callanan and J. McCarthy, (UCC Ireland),

Report:

Photometric and spectroscopic observations of CI CAM, the possible
counterpart of XTE J0421+56 (IAUC 6855, 6857), were obtained with the
1.2m and 1.5m telescopes at the Whipple Observatory during 1998 April
3.08-3.17 UT.  Conditions were photometric with variable 2" seeing.
We find V=9.25 +/- 0.1, B=10.25 +/- 0.1.  This implies a brightening
of more than 2 magnitudes in each band, relative to the levels
measured by Bergner et al (1995 A&A Suppl 112 221).  Relative
photometry of 3 B and 4 V frames yields an upper limit to any short
term photometric variability of <2% during our observations.  Our
spectra, obtained at 3.0 and 0.75 angstrom resolution (covering
4000-7000 angstroms and 6000-7000 angstroms), appear similar to those
of Downes (1984 PASP 96 807), but the level of Fe II and He I
emission has strengthened in comparison to H-Balmer.  He II (4685.3
angstroms) and He I (4712.9 angstroms) are detected with equivalent
widths of 15+/-5 angstroms and 30+/-10 angstroms respectively,
confirming the new HeII emission reported by Wagner et al. (IAUC
6857).  The forest of strong H, He I, and Fe II emission lines
obscures the continuum to the extent that it is unclear if any
photospheric absorption lines are present.  None of the lines in our
spectra show any evidence for the type of double peaked emission
typically arising in x-ray binary or cataclysmic variable accretion
disks.  Our data are consistent with the association of CI Cam with
XTE J0421+56, but imply that this might then be an unusual
symbiotic-type x-ray binary, perhaps akin to GX1+4 or 2A1704+241(=HD154791). 

----------------------------------------------------------------------------

Date: Fri, 03 Apr 1998 18:56:59 -0700
To: garcia@cfa219.harvard.edu (Mike Garcia), BAILYN@astro.yale.edu,
        ajct@laeff.esa.es, chaswell@star.maps.susx.ac.uk,
        e.kuulkers1@physics.oxford.ac.uk, fghigo@nrao.edu,
        garcia@head-cfa.harvard.edu, guy@mrao.cam.ac.uk,
        ewaltman@rsd.nrl.navy.mil, jem@head-cfa.harvard.edu,
        lewin@space.mit.edu, marshall@milkyway.gsfc.nasa.gov,
        pac@astro.ox.ac.uk, rhjellmi@aoc.nrao.edu, rmw@lowell.edu,
        rpf@astro.uva.nl, rr@space.mit.edu, shrader@grossc.gsfc.nasa.gov,
        starrfie@hydro.la.asu.edu, stroh@pcasun1.gsfc.nasa.gov,
        swank@pcasun1.gsfc.nasa.gov, takeshim@ginpo.gsfc.nasa.gov,
        tavani@astro.columbia.edu, narayan@cfa.harvard.edu,
        vsnet-alert@kusastro.kyoto-u.ac.jp, res@jb.man.ac.uk,
        MCCOLLOUGH@bowie.msfc.nasa.gov, jgreiner@aip.de,
        dlevine@iso.vilspa.esa.es
From: "Robert M. Hjellming (Bob)" <rhjellmi@aoc.nrao.edu>
Cc: rhjellmi@arana.aoc.nrao.edu, amiodusz@arana.aoc.nrao.edu,
        mrupen@arana.aoc.nrao.edu
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Precedence: list
X-Distribute: distribute [version 2.1 (Alpha) patchlevel=24]
X-Sequence: vsnet-alert 0
Subject: [vsnet-alert 0] IAU Circular submission on XTE J0421+560 (= CI Cam)
Errors-To: owner-vsnet-alert@kusastro.kyoto-u.ac.jp
Sender: owner-vsnet-alert@kusastro.kyoto-u.ac.jp

The following submission to the IAU Circulars describes
our current conclusion from the VLA data of April 2 and 3.
There will be a long VLBA imaging run on this source 
tomorrow.

If you plot the radio spectra you will see why this
is an EXCEPTIONALLY quickly evolving synchrotron radiation
source.

>Date: Fri, 03 Apr 1998 17:38:13 -0700
>To: BMARSDEN@CFA.HARVARD.EDU, DGREEN@CFA.HARVARD.EDU
>From: "Robert M. Hjellming (Bob)" <rhjellmi@nrao.edu>
>Subject: IAU Circular submission on XTE J0421+560 (= CI Cam)
>Cc: rhjellmi, amiodusz
>
>
>XTE J0421+560 AND CI CAMELOPARDALIS
>
> R. M. Hjellming and A. J. Mioduszewski, National Radio
>Astronomy Observatory, report: "VLA observations of 
>CI Cam on Apr 3.83 UT reveal the presence of an 
>unresolved point source with preliminary flux densities 
>of 120, 470, 650, 500, and 420 mJy at 1.4, 4.9, 8.4, 
>14.9, and 22.5 GHz, respectively.  This indicates that 
>it was optically thick at the two lower frequencies 
>and close to optically thin at the two higher frequencies. 
>The size of the source is less than 0.1" at 22.5 GHz.
>We reanalyzed the 1.4 GHz data for April 2.63 UT (IAUC 6827) 
>and were able to also image the source at 4.9 and 8.4 GHz, 
>so we can report preliminary flux densities of 20, 150, and 
>280 mJy at these three frequencies on April 2.63 UT; at 
>that time the spectrum was optically thick with a spectral 
>index of about 1.5. The rapid variability of factors of ~6, 
>~3, and ~2.3 at 1.4, 4.9, and 8.4 GHz, respectively, 
>indicates that this is synchrotron radio emission which 
>is probably related to the X-ray transient XTE J0421+560 
>(IAUC 6855,6857).  Since the position of the unusual
>radio source coincides with the "symbiotic" star CI Cam, 
>the radio emission and X-ray transient can both be 
>identified with CI Cam."  
>
>
>
>

VSNET Home Page

Return to Daisaku Nogami

vsnet-adm@kusastro.kyoto-u.ac.jp