Multi-wavelength INTEGRAL NEtwork (MINE) observations of the microquasar GRS\,1915+105
Ya\"el Fuchs
We present the international collaboration MINE (Multi-lambda Integral NEtwork) aimed at conducting multi-wavelength observations of X-ray binaries and microquasars simultaneously with the {INTEGRAL} $\gamma$-ray satellite. We will focus on the 2003 March--April campaign of observations of the peculiar microquasar GRS\,1915+105 gathering radio, IR and X-ray data. The source was observed 3 times in the plateau state, before and after a major radio and X-ray flare. It showed strong steady optically thick radio emission corresponding to powerful compact jets resolved in the radio images, bright near-infrared emission, a strong QPO at 2.5\,Hz in the X-rays and a power law dominated spectrum without cutoff in the 3--300\,keV range. We compare the different observations, their multi-wavelength light curves, including JEM-X, ISGRI and SPI, and the parameters deduced from fitting the spectra obtained with these instruments on board {INTEGRAL}.
fuchs.tex
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\title{Multi-wavelength INTEGRAL NEtwork (MINE) observations of the
microquasar GRS\,1915+105}
\author{Ya\"el Fuchs}
\affil{Service d'Astrophysique, CEA/Saclay, Orme des Merisiers b\^at. 709, 91191 Gif sur Yvette cedex, France}
\author{J. Rodriguez$^{1,}$}
\affil{Integral Science Data Centre, Chemin d'Ecogia, 16, CH-1290 Versoix, Switzerland}
%\affil{}
\author{S. E. Shaw$^{2,}$}
\affil{School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ UK}
\author{P. Kretschmar$^{2,}$}
\affil{Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, 85748 Garching, Germany}
\author{M. Rib\'o$^{1}$, S. Chaty$^{1,}$}
\affil{Universit\'e Paris 7, 2 place Jussieu, 75005 Paris, France}
\author{I.~F.~Mirabel$^{1,}$}
\affil{Instituto de Astronom\'\i a y F\'\i sica del Espacio / CONICET, 
cc67, suc 28. 1428 Buenos Aires, Argentina}
\author{V. Dhawan}
\affil{National Radio Astronomy Observatory, Socorro, NM 87801, USA}
\author{G. G. Pooley}
\affil{Mullard Radio Astronomy Observatory, Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE, UK}
\author{I. Brown}
\author{R. Spencer}
\affil{University of Manchester, Jodrell Bank Observatory, Macclesfield, Cheshire SK11 9DL}
\author{D. C. Hannikainen}
\affil{Observatory, University of Helsinki, PO Box 14, FIN-00014 , Finland}

\newcommand{\btx}{\textsc{Bib}\TeX}
\newcommand{\filename}{esapub}

\begin{document}

\keywords{Stars: individual: GRS\,1915+105 -- X-rays: binaries -- 
	Gamma rays: observations -- ISM: jets and outflows}

\maketitle

\begin{abstract}
We present the international collaboration MINE (Multi-lambda Integral
NEtwork) aimed at conducting multi-wavelength observations of X-ray
binaries and microquasars simultaneously with the {\it INTEGRAL}
$\gamma$-ray satellite. We will focus on the 2003 March--April
campaign of observations of the
peculiar microquasar GRS\,1915+105 gathering radio, IR and X-ray
data. The source was observed 3 times in the plateau state, before and
after a major radio and X-ray flare. 
   It showed strong steady optically thick radio emission corresponding to 
   powerful compact jets resolved in the radio images, 
   bright near-infrared emission, a strong QPO at 2.5\,Hz in the X-rays
   and a power law dominated spectrum without cutoff in the 3--300\,keV range. 
We
compare the different observations, their multi-wavelength light
curves, including JEM-X, ISGRI and SPI, and the parameters deduced
from fitting the spectra obtained with these instruments on board
{\it INTEGRAL}.
\end{abstract}

\section{Introduction}
	Microquasars are X-ray binaries that produce relativistic jets
	and thus appear as miniature replicas of distant quasars
	\citep{mirabelrodriguez99}.
%	\citep{mirabelrodriguez99}. 
	Their emission
	spectra, variable with time, range from the radio to the
	$\gamma$-ray wavelengths.
% MINE
	We present here the first multi-wavelength campaign on
	GRS\,1915+105 involving the {\it INTEGRAL} satellite (3\,keV--10\,MeV).
	This campaign was conducted by the MINE
	(\mbox{Multi-$\lambda$} {\it INTEGRAL} NEtwork, see
	{\sf http://elbereth.obspm.fr/$\sim$fuchs/mine.html}) international
	collaboration aimed at performing multi-wavelength
	observations of galactic X-ray binaries simultaneously with
	{\it INTEGRAL}.


\section{GRS\,1915+105}
	The microquasar GRS\,1915+105 is extremely variable at all
	wavelengths (see \citealt{fuchs03} for a review).  It hosts the
	most massive known stellar mass black hole of our Galaxy with
	M$=14.0\pm4.4$\,M$_{\odot}$ %(Greiner et al.\@ 2001).
	\citep{greiner01Nat, harlaftis04}.  
	In the radio %domain 
	it can show superluminal ejections at arcsec scales
%	(Mirabel \& Rodr\'\i guez 1994)
	\citep{mirabelrodriguez94}
%	giving an upper limit of 11.2$\pm$0.8\,kpc to the
%	distance of the source (Fender et al.\@ 1999),
	leading to a maximum distance of 11.2$\pm$0.8\,kpc 
%(Fender et al.\@ 1999),
	\citep{fender99}, 
	and  
	compact jets at milli-arcsecond scales %(Dhawan et al.\@ 2000).
	(= a few tens of AU, \citealt{dhawan00}).
%Dhawan et al.\@ 2000).
	 
%	The presence of such a compact and quasi-steady
%	radio jet is now commonly inferred in the low/hard X-ray state
%	of several microquasars but it is rarely resolved (see
%	\cite{fender03} and references therein).

%dates of observations
	We conducted a multi-wavelength observation campaign of
	GRS\,1915+105 on 
%spring 2003 (see Figure~\ref{figcamp}).
	March 24--25, April 2--3 and April 17--18 2003 (see
	Fig.~\ref{figcamp}) corresponding to {\it INTEGRAL}
	revolutions 54, 57 and 62, respectively.  Here we focus only on
	the April observations when ToO (Targets of Opportunity) were
	triggered by the MINE collaboration.  This (nearly)
	simultaneous campaign involved the VLA, the VLBA, MERLIN and
	the Ryle Telescope (RT) in radio, the ESO/NTT in IR, {\it
	RXTE} and {\it INTEGRAL} in X/$\gamma$-rays. More details and
	description of the April 2 observations can be found in 
%Fuchs et al.\@ (2003b).  
	\citet{fuchsmine03}.
%Fuchs \etal\ (2003b).

\begin{figure}[!ht]
   \centering
%  If you have a figure, remove the comments % before...
%   \includegraphics[width=9cm]{author1_fig1.ps}
%   \vspace*{-0.4cm}
   \includegraphics[angle=-90,width=\columnwidth]{yfuchs_fig1.ps}
%   \vspace*{-0.3cm}
      \caption{Viewgraph of the observing campaign in spring
      2003, indicating the dates, time and involved observatories (GPS
      = Galactic Plane Survey of {\it INTEGRAL}).}
       \label{figcamp}
\end{figure}

\begin{figure}[!ht]
   \centering
   \includegraphics[width=\columnwidth]{figep1915-RadioX-fevap03.ps}
   \vspace*{-0.3cm}
      \caption{Radio and X-ray flux monitoring of GRS\,1915+105 in
      March--April 2003.  Radio: Nan\c cay at 1.41 \& 2.69~GHz, RATAN at
      3.9, 7.7 \& 11.2~GHz, VLA at 8.4 \& 22~GHz, RT at
      15\,GHz. X-ray: quick-look results provided by the ASM/RXTE
      team. The dashed lines indicate the dates of our INTEGRAL and
      simultaneous multi-wavelength observations.  The RATAN flux
      densities were kindly provided by Sergei Trushkin.  The Nan\c cay
      flux densities were kindly provided by Harry Lehto and Emilios
      Harlaftis.
%The VLA 8.4 and 22 GHz flux densities in the top panel are part of the MINE observing campaign. 
}
       \label{figclgen}
\end{figure}


\begin{figure}[!ht]
   \centering
   \includegraphics[width=\columnwidth]{yfuchs_fig2.eps}
   \vspace*{-0.3cm}
      \caption{X/$\gamma$-ray spectra and fit of
   GRS\,1915+105 measured with {\it RXTE} \& {\it INTEGRAL}
    on April 2, 2003 (rev.\,57). 
   The structures at $E$$>$50\,keV in
   the SPI spectrum are instrumental background lines not adequately corrected.
   The PCA power density spectrum (inset)
   shows a clear QPO at 2.5\,Hz.}
       \label{figspec}
\end{figure}

\begin{figure}[!ht]
   \centering
   \includegraphics[width=\columnwidth]{1915_rev62-spectra-white-jemx-isgri-spi.eps}
   \vspace*{-0.3cm}
      \caption{X/$\gamma$-ray spectra and fit of
   GRS\,1915+105 measured with {\it INTEGRAL} on April 17--18, 2003 
   (rev.\,62).}
       \label{figspec18av}
\end{figure}

\begin{figure}[!ht]
   \centering
   \includegraphics[width=\columnwidth]{fig1915-courbeslum-2ap03-new.ps}
   \vspace*{-0.3cm}
      \caption{Light curves of the multi-wavelength observations on
      April 2--3, 2003 (rev.\,57) involving INTEGRAL/ISGRI \& SPI (not
      plotted), RXTE/PCA \& HEXTE (not plotted), ESO/NTT, RT, VLA and
      VLBA (total flux densities spanning the observing time).
%only the time interval is plotted.
%the detected total integrated flux density at 15\,GHz spanning
%the observing time is plotted.
%Viewgraph of the whole observing campaign in spring 2003, 
%indicating the dates, time 
%and involved observatories. The observations discussed in this letter are of April 2--3.
}
       \label{figcl2av}
\end{figure}

\begin{figure}[!ht]
   \centering
   \includegraphics[width=\columnwidth]{fig1915-courbeslum-18ap03.ps}
   \vspace*{-0.3cm}
      \caption{Light curves of the multi-wavelength observations on 
	April 17--18, 2003 (rev.\,62) involving INTEGRAL/ISGRI \& SPI, 
	RT, MERLIN, VLA and VLBA 
	(total flux densities spanning the observing time).
	The difference between the flux levels of ISGRI and SPI is due 
	to calibration.}
       \label{figcl18av}
\end{figure}

\begin{figure}[!ht]
   \centering
   \includegraphics[width=\columnwidth]{yfuchs_fig3.ps}
   \vspace*{-0.3cm}
      \caption{VLBA images at 2.0 \& 3.6\,cm on April~2, 2003 showing
      the compact jet. 
%Total integrated flux densities are 123 \&
%      116\,mJy, respectively, in agreement with a slightly inverted
%       spectrum. The convolving beams are 1.4 \& 2.8\,mas,
%       respectively.  
	1\,mas = 12\,AU at 12\,kpc.} 
%	The rms noise in both maps is 0.15\,mJy\,beam$^{-1}$.}
       \label{figjet}
\end{figure}

\begin{figure}[!ht]
   \centering
   \includegraphics[angle=-90,width=\columnwidth]{GRS1915_MERLIN_APRIL17.PS}
   \vspace*{-0.3cm}
      \caption{MERLIN 18\,cm (1.658\,GHz) image of GRS\,1915+105 
	on April 17--18, 2003.}
       \label{figmerlin}
\end{figure}

	Fig.~\ref{figclgen} shows the general radio and X-ray
	behaviour of GRS\,1915+105 during our observing campaign.
	After a period of X-ray oscillations (end of February --
	beginning of March) giant radio flares occured around MJD
	52714 (March 15) and MJD 52734 (April 5). The latter may be a
	double flare since there are two X-ray flares in the {\it
	RXTE}/ASM light curve, and it probably corresponds to major
	superluminal ejections.
%	the flux densities become 
%	more quiet, with a slowly decaying ASM flux $\sim50$\,counts.s$^{-1}$,
%	although the radio level is still very high (>100\,mJy). 
%	X-ray flaring episodes occurred again in MJD 52732--52737 and also a giant radio flare, 
%	then the radio and X-ray fluxes are quiet again after MJD 52742. 
%	Each of our observing campaigns occurred during a quiet period.
%	Despite X-ray oscillating and flaring episodes and two giant
%	Despite X-ray and giant 
%	radio flaring episodes that occurred in March--April 2003,
	Despite these flaring episodes, our
	observations took place during the \emph{plateau}
	state of GRS\,1915+105 \citep{fender99,kleinwolt02} 
%(Fender et al.\@\,1999)
	i.e.\@ quasi-steady
	 {\it RXTE}/ASM (2--12\,keV) flux
	$\sim$50\,cts/s and  high steady radio level 
	($>$100\,mJy).
%%This \emph{plateau} state is also called the radio loud low/hard X-ray state.
	This \emph{plateau} state was observed on several past occasions in
	GRS\,1915+105 (see e.g. Fig.\,1 of \citealt{muno01}) and was
	also called the radio loud low/hard X-ray state \citep{muno01}
	and type II state \citep{trudolyubov01}. It also corresponds
	to the $\chi_1$ and $\chi_3$ X-ray classes of
	\citet{belloni00} who used PCA color-color diagram, and indeed
	our April 2 observation appears as the $\chi_1$ class when
	plotted in such a diagram.

	On April\,2 (Fig.~\ref{figspec}) \& 18 (Fig.~\ref{figspec18av})
	the high energy emission 
	shows a power law dominated spectrum ($>$60\% at
	3--20\,keV) with a photon index $\Gamma$=2.9 and 2.75, respectively. 
	This state is much softer 
%	$\Gamma$$\sim$3) 
	than the classical low/hard state of the other BH binaries 
	and is closer to the very high or intermediate states
%	(McClintock \& Remillard 2004).
	\citep{mcclintock04}. 
%	previously compared to the plateau state of the source. 
	The {\it INTEGRAL} observations
%	(Fig.~\ref{figspec})
	show that this power law spectrum extends up to 300\,keV
	without any cutoff during this \emph{plateau} state, consistent with
	the observations with {\it CGRO}/OSSE 
%	(Zdziarski et al.\@ 2001).
	\citep{zdziarski01}.
%on borad of the CGRO satellite.
%
	The estimated luminosity on April 2 is 
	$\sim$\,$7.5$\,$\times$\,$10^{38}$\,erg\,s$^{-1}$, 
	using the {\it RXTE}/PCA (2--30\,keV) which overestimates the flux 
	by about 16\%. 	
	On April 18 the luminosity is 
	$\sim$\,$2.8$\,$\times$\,$10^{38}$\,erg\,s$^{-1}$ using {\it
	INTEGRAL}/JEM-X (3--30\,keV).
	These values correspond to 40\% and 16\%, 
	respectively,
	of the Eddington luminosity for a $14M_{\odot}$ black hole.
%
	As shown in Fig.~\ref{figspec}, a very
	clear Quasi-Periodic Oscillation (QPO) at 2.5\,Hz with a 14\%
	rms level was observed in the {\it RXTE}/PCA signal, 
	which is
%	The strong QPO at 2.5\,Hz observed on April 2 is 
	consistent with the previous observations of the \emph{plateau} state
	(see also \citealt{rodriguez04}).%Rodriguez et al.\@ 2003).
%	The presence of the 0.5--10\,Hz
%	QPO seems correlated to a hard tail in the energy spectra 
%	of the source (\cite{muno99}). 

%  light curves
	The detailed light curves of our observations on April~2--3
	(Fig.~\ref{figcl2av}) and April~17--18 (Fig.~\ref{figcl18av}) 
	show nearly quiet flux densities
	when compared to flares or oscillations, with variations
	$\lesssim$20\% at all wavelengths
	(the peaks in the ISGRI and SPI light curves are not real).
	The most interesting phenomenon is on April~2, a moderate $\sim$25\%
	decrease (from 4.9 to 3.6\,mJy) in the $K_{\mathrm s}$ flux density 
	lasting 20\,min which precedes by 31\,min a $\sim$20\% decrease in
	the RT signal (from 145 to 118\,mJy) lasting 48\,min.  This 
%%	is consistent with 
	may be due to instabilities in the jet
%%a decrease in the jet power 
	inducing an
	immediate synchrotron response in the IR and the delay being
	due to the time for the material along the jet to become
	optically thin to the radio emission \citep{mirabel98}. 
	The radio and near-IR flux densities are high in both observations.

%	radio compact jet
	The VLBA high resolution images on April 2
	(Fig.~\ref{figjet}) show the presence of a compact
	radio jet with a $\sim$7--14\,mas length (85--170\,AU at
	12\,kpc).
	These jets are also observed in the radio images on March~24 
	and April~19.
% 	This jet is responsible for the high radio levels measured in radio
%	by its optically thick synchrotron emission.
	The optically thick synchrotron emission from this jet is
	responsible for the high radio levels observed during the
	\emph{plateau} state of GRS\,1915+105 (see Fig.~\ref{figclgen},
	Fig.~\ref{figcl2av} and Fig.~\ref{figcl18av}).  On April 18
	the MERLIN image (Fig.~\ref{figmerlin}) shows a radio extension
	of $\sim$0.3$''$. This extension is likely
% which is probably 
	the trace of a superluminal ejection occurred around April~4
	(corresponding to the giant radio flare of April~5 on
	Fig.~\ref{figclgen}) since it would correspond to a mean
	velocity of $\sim$\,21\,mas/d compatible with the previous
	observations (\citealt{mirabelrodriguez99}).

\begin{figure}[!tbp]
\includegraphics[width=\columnwidth]{Fh042_f5.ps}
\vspace*{-0.7cm}
\caption{
   Spectral energy distribution of GRS\,1915+105 on April~2. The
   near-IR flux densities were dereddened with $A_V$\,=\,19.5 and
   using eq.\,1 of \citet{cardelli89}. The dot-dashed line illustrates
   the optically thick synchrotron emission from the jet as a power
   law with $F_\nu\propto\nu^{-0.12}$. The dashed line illustrates a
   power law with a photon index $\Gamma$=3. Error bars not shown are
   smaller than the symbol size.  }
\label{figsed}
\end{figure}


%	IR
	On April\,2 the source was fairly bright in near-IR 
	with an excess of 75--85\%
	in the $K_{\mathrm s}$-band compared to the $K$=14.5--15\,mag.\@
	of the K-M giant donor star of the binary.
	According to the spectral energy distribution (Fig.~\ref{figsed}), 
	this IR excess is 
	compatible with a strong contribution from
	the synchrotron emission of the jet extending from the radio
	up to the near-IR. 
%	However, the $J$, $H$, and $K_{\mathrm s}$ dereddened flux
%	densities are not compatible with such a single power law
%	emission, since
%	a significant change in the slope appears
%	at the $H$-band. This H band
%	However, 
%	different components add to the jet emission 
	Different components, however, contribute to the IR
	in addition to the jet,
	such as the donor-star, the external part of the
	accretion disc or free-free emission.

\section{Conclusions and Prospects}
	Here for the first time, we observed simultaneously all the
	properties of the \emph{plateau} state of GRS\,1915+105\,: 
%	that were previously observed individually.
	a powerful compact
	radio jet, responsible for the strong steady radio emission and
	probably for a significant part of the bright near-IR
	emission, as well as a QPO (2.5\,Hz) in the X-rays 
	and a power law dominated X-ray spectrum with
	a $\Gamma$$\sim$3 photon index up to at least
	300\,keV. Forthcoming works will study
	detailed fits of the X-ray spectra, 
	to determine for example
	whether this power law is due to an inverse Compton
	scattering of soft disc photons 
	on the base of the compact jet 
	or not.
%	 will be studied in forthcoming papers.
	In order to better
	understand the unusual behaviour of GRS\,1915+105, we need to
	carry out similar simultaneous broad-band campaigns during the
	other states, in particular during the sudden changes 
	 that correspond to powerful relativistic
	ejection events.


\section*{Acknowledgments}
%Y.F. and J. R. acknowledge CNES fellowships.
  Y.F. and J.R. acknowledge financial support from the CNES.
  M.R. acknowledges support from a Marie Curie individual fellowship under
contract No.\,HPMF-CT-2002-02053.
  D.C.H. acknowledges the Academy of Finland for financial support.
  The National Radio Astronomy Observatory is a facility of
the National Science Foundation operated under cooperative agreement by
Associated Universities, Inc.
  Based on observations collected at the European Southern Observatory,
Chile (ESO N$^\circ$ 071.D-0073).
  We thank the ASM/RXTE team for providing the quick-look results.
  We thank Sergei Trushkin for the RATAN data, 
and Harry Lehto and Emilios Harlaftis for the Nan\c cay data.
%  The following bibliography was produced with
    \bibliographystyle{aa}
%    \bibliography{esapub}
\bibliography{ref1915-munich}

 \end{document}

fuchs.bbl
\begin{thebibliography}{17}
\expandafter\ifx\csname natexlab\endcsname\relax\def\natexlab#1{#1}\fi
\expandafter\ifx\csname url\endcsname\relax
  \def\url#1{{\tt #1}}\fi
\expandafter\ifx\csname urlprefix\endcsname\relax\def\urlprefix{URL }\fi

\bibitem[{{Belloni} et~al.(2000){Belloni}, {Klein-Wolt}, {M{\' e}ndez}, {van
  der Klis}, \& {van Paradijs}}]{belloni00}
{Belloni} T., {Klein-Wolt} M., {M{\' e}ndez} M., {van der Klis} M., {van
  Paradijs} J., 2000, \aap, 355, 271

\bibitem[{{Cardelli} et~al.(1989){Cardelli}, {Clayton}, \&
  {Mathis}}]{cardelli89}
{Cardelli} J.A., {Clayton} G.C., {Mathis} J.S., 1989, \apj, 345, 245

\bibitem[{{Dhawan} et~al.(2000){Dhawan}, {Mirabel}, \& {Rodr\'\i
  guez}}]{dhawan00}
{Dhawan} V., {Mirabel} I.F., {Rodr\'\i guez} L.F., 2000, \apj, 543, 373

\bibitem[{{Fender} et~al.(1999){Fender}, {Garrington}, {McKay}
  et~al.}]{fender99}
{Fender} R.P., {Garrington} S.T., {McKay} D.J., et~al., 1999, \mnras, 304, 865

\bibitem[{{Fuchs} et~al.(2003{\natexlab{a}}){Fuchs}, {Mirabel}, \&
  {Claret}}]{fuchs03}
{Fuchs} Y., {Mirabel} I.F., {Claret} A., 2003{\natexlab{a}}, \aap, 404, 1011

\bibitem[{{Fuchs} et~al.(2003{\natexlab{b}}){Fuchs}, {Rodriguez}, {Mirabel}
  et~al.}]{fuchsmine03}
{Fuchs} Y., {Rodriguez} J., {Mirabel} I.F., et~al., 2003{\natexlab{b}}, \aap,
  409, L35

\bibitem[{{Greiner} et~al.(2001){Greiner}, {Cuby}, \&
  {McCaughrean}}]{greiner01Nat}
{Greiner} J., {Cuby} J.G., {McCaughrean} M.J., 2001, \nat, 414, 522

\bibitem[{{Harlaftis} \& {Greiner}(2004)}]{harlaftis04}
{Harlaftis} E.T., {Greiner} J., 2004, \aap, 414, L13

\bibitem[{{Klein-Wolt} et~al.(2002){Klein-Wolt}, {Fender}, {Pooley}
  et~al.}]{kleinwolt02}
{Klein-Wolt} M., {Fender} R.P., {Pooley} G.G., et~al., 2002, \mnras, 331, 745

\bibitem[{{McClintock} \& {Remillard}(2004)}]{mcclintock04}
{McClintock} J.E., {Remillard} R.A., 2004, in 'Compact Stellar X-Ray Sources',
  eds. W.H.G. Lewin and M. van der Klis, CUP, astro-ph/0306213

\bibitem[{{Mirabel} \& {Rodr\'\i guez}(1994)}]{mirabelrodriguez94}
{Mirabel} I.F., {Rodr\'\i guez} L.F., 1994, \nat, 371, 46

\bibitem[{{Mirabel} \& {Rodr{\'{\i}}guez}(1999)}]{mirabelrodriguez99}
{Mirabel} I.F., {Rodr{\'{\i}}guez} L.F., 1999, \araa, 37, 409

\bibitem[{{Mirabel} et~al.(1998){Mirabel}, {Dhawan}, {Chaty}
  et~al.}]{mirabel98}
{Mirabel} I.F., {Dhawan} V., {Chaty} S., et~al., 1998, \aap, 330, L9

\bibitem[{{Muno} et~al.(2001){Muno}, {Remillard}, {Morgan} et~al.}]{muno01}
{Muno} M.P., {Remillard} R.A., {Morgan} E.H., et~al., 2001, \apj, 556, 515

\bibitem[{{Rodriguez} et~al.(2004){Rodriguez}, {Fuchs}, {Hannikainen}
  et~al.}]{rodriguez04}
{Rodriguez} J., {Fuchs} Y., {Hannikainen} D.C., et~al., 2004, this volume

\bibitem[{{Trudolyubov}(2001)}]{trudolyubov01}
{Trudolyubov} S.P., 2001, \apj, 558, 276

\bibitem[{{Zdziarski} et~al.(2001){Zdziarski}, {Grove}, {Poutanen}, {Rao}, \&
  {Vadawale}}]{zdziarski01}
{Zdziarski} A.A., {Grove} J.E., {Poutanen} J., {Rao} A.R., {Vadawale} S.V.,
  2001, \apjl, 554, L45

\end{thebibliography}
