Since the beginning of it's mission, INTEGRAL has been monitoring the Galactic
Centre and as a result has discovered many new high-energy radiation sources in
the region. The above image shows the Galactic Centre region as seen with an RGB
colour composite INTEGRAL/IBIS HiPS (
Hierarchical progressive survey)
map, in the web application ESASky.
The central pink cross shows the position of the supermassive black hole Sagittarius A*,
while the blue crosses represent the centre of each INTEGRAL observation. ESASky is
an interactive science-driven discovery portal, providing users with direct links
to observational data. For example, each INTEGRAL observation ID number can be selected
in the data panel and takes the user to the INTEGRAL Science Data Archive at ISDC,
providing the full group of pointings for that particular observation. Additionally,
the INTEGRAL IBIS/ISGRI Soft Gamma-Ray Source Catalog can be displayed along with
catalogues and observation footprints from a large number of space astronomy missions,
accessible from the data panel in the lower half of the application.
The INTEGRAL-IBIS RGB HiPS map was constructed from all public data (up to October 2015)
with red at 20-35 keV, green at 35-65 keV and blue at 65-100 keV. These data were
processed in subsets based on proximity in time and space, before being combined into the
set of mosaics subsequently used to generate the all-sky map. Each energy band was processed
separately. The cuts in the value of significance in each band were defined such that a
black hole with hard emission (e.g. with a power-law photon spectral index of ~2) appears
bluish-white, and neutron stars with steeper (softer) spectra look red-orange. For example,
the blue-white source seen to the right of Sgr A* is the galactic centre microquasar
1E 1740.7-2942, also known as the "Great Annihilator", and the bright red source to the
upper left of Sgr A* is the luminous neutron-star low-mass X-ray binary GX 3+1.
About ESASky
ESASky is an open science web application
providing full access to the entire sky as observed across the electromagnetic spectrum
with space astronomy missions of ESA and partner agencies. As of August 2017, the missions
included in ESASky are Chandra (NASA), Gaia, Herschel, Hipparcos, Hubble (NASA/ESA),
INTEGRAL, ISO, Planck, Suzaku (NASA/JAXA) and XMM-Newton. Users can visualise and download
all public high-quality data from these astronomy missions, including science-ready images
(in FITS format) and sources catalogues. A simple python interface from the
astropy astroquery package
enables users to browse and retrieve all the data and catalogues in ESASky.
ESASky is routinely updated with the latest, highest quality data, and works as a top-level
search interface to the riches of space astronomy science archives, to which it provides
direct access.
ESASky is developed by the
ESAC Science Data Centre and makes use of Aladin Lite, a lightweight sky atlas running
in the browser, developed by the Centre de Données astronomiques de Strasbourg (CDS),
Strasbourg Observatory, France.
INTEGRAL-IBIS RGB HiPS map created by G. Belanger (INTEGRAL SOC)
References:
"Visualization of Multi-mission Astronomical Data with ESASky"
Baines, Deborah; Giordano, Fabrizio; Racero, Elena; Salgado, Jesús; López Martí, Belén;
Merín, Bruno; Sarmiento, María-Henar; Gutiérrez, Raúl; Ortiz de Landaluce, Iñaki;
León, Ignacio; de Teodoro, Pilar; González, Juan; Nieto, Sara; Segovia, Juan Carlos;
Pollock, Andy; Rosa, Michael; Arviset, Christophe; Lennon, Daniel; O'Mullane, William;
de Marchi, Guido
2017, PASP, 129, 972, 028001
http://adsabs.harvard.edu/abs/2017PASP..129b8001B
