文件操作 - 1781506996.M375926P16584.mail.planetcloud-host.com,S=5626,W=5718:2,

文件: /var/vmail/bicar.it/stefano/cur/1781506996.M375926P16584.mail.planetcloud-host.com,S=5626,W=5718:2,

编辑文件内容

Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=174.142.199.243; helo=server.astronomerstelegram.org; envelope-from=atel@astronomerstelegram.org; receiver=stefano@bicar.it 
To: stefano@bicar.it
From: atel@astronomerstelegram.org
Subject: ATel  17843
Message-Id: <20260615070312.9031B288081F@server.astronomerstelegram.org>
Date: Mon, 15 Jun 2026 03:03:12 -0400 (EDT)

------------------------------------------------------------------------------ 
The Astronomer's Telegram is free to read, free to publish, free to
use.  Thanks to the support of our patrons, we can continue to
keep it free. https://www.patreon.com/astronomerstel
------------------------------------------------------------------------------ 
The Astronomer's Telegram                   http://www.astronomerstelegram.org 
------------------------------------------------------------------------------
Posted: Within the last 24 hours
==============================================================================
ATEL #17843							     ATEL #17843

Title:	Fermi-LAT detection of recent gamma-ray activity from Cygnus
		X-3
Author:	P. van Zyl (SARAO, South African Radio Astronomy Observatory),
		P. Monti-Guarnieri (University of Trieste and INFN Trieste), G. La
		Mura (INAF-OAC), J. Valverde (Marquette University), and M. Giroletti
		(INAF-IRA Bologna), on behalf of the Fermi Large Area Telescope Collaboration
Queries:	pfesi24@gmail.com
Posted:	14 Jun 2026; 15:18 UT
Subjects:Gamma Ray, Binary

The Large Area Telescope (LAT), one of the two instruments on the Fermi
Gamma-ray Space Telescope, has observed renewed gamma-ray activity from
the high mass X-ray binary Cygnus X-3, also known as 4FGL J2032.6+4053
(The Fermi-LAT collaboration 2020, ApJS, 247, 1), with coordinates R.A.
= 308.10737 deg, Decl. =  40.95775 deg (J2000; Petrov 2012, MNRAS, 419,
1097).

Preliminary analysis indicates that this source was in an elevated gamma-ray
emission state on June 13, 2026, with a daily averaged gamma-ray flux (E>100MeV)
of (2.6+/- 0.4) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only).
This corresponds to a flux increase of a factor of approximately 20 relative
to the average flux reported in the fourth data release of the fourth Fermi-LAT
source catalog (4FGL-DR4, Ballet et al. 2023, arXiv:2307.12546). The corresponding
photon index is  2.6 +/- 0.1, and it is consistent with the 4FGL-DR4 value
of 2.68 +/- 0.04 within uncertainties. On a weekly time scale the source
is significantly detected by the "Fermi All-sky Variability Analysis" (FAVA)
between June 1 and June 8 in the low energy band (100 MeV - 800 MeV), but
not in the high energy one (800 MeV - 300 GeV). It is however significantly
detected in the energy range 100 MeV - 300 GeV between June 4 and June
11, being also associated with a E=25 GeV photon, detected on June 11 at
11:23:02 UT with a source association probability p > 0.975. The Fermi-LAT
Collaboration has previously reported flaring activity from this source
in ATel #10243. Radio and gamma-ray flaring activity has also recently
been reported in ATel #17836.

Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray
monitoring of this source will continue. A preliminary light curve for
Cygnus X-3 can be accessed via the Fermi-LAT Light Curve Repository at
<a href="https://fermi.gsfc.nasa.gov/ssc/data/access/lat/lcr/source.html?source_name=4FGL_J2032.6+4053">4FGL
J2032.6+4053</a>. Since the source is part of the list of LAT daily monitored
sources, its daily light curve can also be accessed at <a href="https://fermi.gsfc.nasa.gov/ssc/data/access/lat/msl_lc/source/Cygnus_X-3">Cygnus
X-3</a>. We encourage multifrequency observations of this source. For this
source the Fermi-LAT contact person is Stephane Corbel (stephane.corbel@cea.fr).

The Fermi-LAT is a pair conversion telescope designed to cover the energy
band from 20 MeV to greater than 300 GeV. It is the product of an international
collaboration between NASA and DOE in the U.S. and many scientific institutions
across France, Italy, Japan and Sweden.

------------------------------------------------------------------------------
Password Certification: Pfesesani van Zyl (pfesi24@gmail.com)
https://www.astronomerstelegram.org/?read=17843
==============================================================================

==============================================================================
This is an automatically-generated notice.  You can remove yourself permanently
from receiving both the Daily Email Digest and Instant Email Notices from
The Astronomer's Telegram by following this link:
https://www.astronomerstelegram.org?unsubscribe&confirmation=a803d34e7ea924f9a4142bac00763549&address=stefano@bicar.it

文件操作 - 1781506996.M375926P16584.mail.planetcloud-host.com,S=5626,W=5718:2,

文件: /var/vmail/bicar.it/stefano/cur/1781506996.M375926P16584.mail.planetcloud-host.com,S=5626,W=5718:2,

编辑文件内容

修改文件时间

删除文件