82
2 Observations of Radio and X-ray Pulsars
three European photon imaging cameras, two reflection grating spectrometers and
one optical monitor. The photon imaging cameras consist of two MOS-CCD cameras
and a single p–n CCD camera, with a total FOV of 30 arc-minutes and an energy
sensitivity range between 0.15 and 15 keV. The reflection grating spectrometers are
a secondary system on the spacecraft and are composed of two focal plane cameras
and their associated reflection grating arrays. This system, operating in the energy
range from 0.35 to 2.5 keV, is used to build X-ray spectral data, and it can determine
the elements presented in the target, as well as the temperature, quantity and other
characteristics of those elements. The optical monitor is a 30-cm optical-ultraviolet
telescope designed to provide simultaneous observations alongside the spacecraft’s
X-ray instruments. The monitor is sensitive between 170 and 650 nm in the FOV of
17
× 17
, co-aligned with the center of the X-ray telescope’s field of view.
In 2006, the XMM-Newton was used to discover the galaxy cluster XMMXCS
2215–1738, 10 billion light year away from Earth, whose mass is about 500 trillion
solar masses. This cluster is surprisingly large and evolved for a cluster that existed
when the universe was only 3 billion years old. In 2011, a flare that lasted 4 h at a
peak intensity of 10,000 times the normal rate was observed by the XMM-Newton,
from an observation of Super-giant Fast X-ray Transient IGR J18410-0535, where a
blue super-giant star sheds a plume of matter that was partly ingested by a smaller
companion neutron star with accompanying X-ray emissions. In 2013, the spin rate
of a super-massive black hole at the core of galaxy NGC 1365 was firstly measured by
the XMM-Newton along with the NuSTAR, a space-based X-ray telescope launched
in 2012 that uses a conical approximation to a Wolter telescope to focus high-energy
X-rays from astrophysical sources and operates in the energy band of 3–79 keV. At
the same time, it verified the model that explains the distortion of X-rays emitted
from a black hole. In 2014, the monochromatic signal around 3.5 keV was extracted
from the spectrum of X-ray emissions observed by the XMM-Newton. This signal
is coming from different galaxy clusters, and several scenarios of dark matter can
justify such a line.
2.9 Observability of X-ray Pulsars
2.9.1 Early X-ray Detections
It is shown from studies that the visible and radio signals are emitted from the Crab
Nebula by the synchrotron-radiation mechanism. If there are some higher energy
charged particles in the Crab Nebula, it is also possible to emit high-energy Xrays by the synchrotron radiation. And thus, the X-ray radiations from the Crab
Nebula should be similar to the visible light, and there is an extended radiation area.
Meanwhile, there could be a compact center object in the Crab Nebula, from which
X-rays are emitted.
2 Observations of Radio and X-ray Pulsars
three European photon imaging cameras, two reflection grating spectrometers and
one optical monitor. The photon imaging cameras consist of two MOS-CCD cameras
and a single p–n CCD camera, with a total FOV of 30 arc-minutes and an energy
sensitivity range between 0.15 and 15 keV. The reflection grating spectrometers are
a secondary system on the spacecraft and are composed of two focal plane cameras
and their associated reflection grating arrays. This system, operating in the energy
range from 0.35 to 2.5 keV, is used to build X-ray spectral data, and it can determine
the elements presented in the target, as well as the temperature, quantity and other
characteristics of those elements. The optical monitor is a 30-cm optical-ultraviolet
telescope designed to provide simultaneous observations alongside the spacecraft’s
X-ray instruments. The monitor is sensitive between 170 and 650 nm in the FOV of
17
× 17
, co-aligned with the center of the X-ray telescope’s field of view.
In 2006, the XMM-Newton was used to discover the galaxy cluster XMMXCS
2215–1738, 10 billion light year away from Earth, whose mass is about 500 trillion
solar masses. This cluster is surprisingly large and evolved for a cluster that existed
when the universe was only 3 billion years old. In 2011, a flare that lasted 4 h at a
peak intensity of 10,000 times the normal rate was observed by the XMM-Newton,
from an observation of Super-giant Fast X-ray Transient IGR J18410-0535, where a
blue super-giant star sheds a plume of matter that was partly ingested by a smaller
companion neutron star with accompanying X-ray emissions. In 2013, the spin rate
of a super-massive black hole at the core of galaxy NGC 1365 was firstly measured by
the XMM-Newton along with the NuSTAR, a space-based X-ray telescope launched
in 2012 that uses a conical approximation to a Wolter telescope to focus high-energy
X-rays from astrophysical sources and operates in the energy band of 3–79 keV. At
the same time, it verified the model that explains the distortion of X-rays emitted
from a black hole. In 2014, the monochromatic signal around 3.5 keV was extracted
from the spectrum of X-ray emissions observed by the XMM-Newton. This signal
is coming from different galaxy clusters, and several scenarios of dark matter can
justify such a line.
2.9 Observability of X-ray Pulsars
2.9.1 Early X-ray Detections
It is shown from studies that the visible and radio signals are emitted from the Crab
Nebula by the synchrotron-radiation mechanism. If there are some higher energy
charged particles in the Crab Nebula, it is also possible to emit high-energy Xrays by the synchrotron radiation. And thus, the X-ray radiations from the Crab
Nebula should be similar to the visible light, and there is an extended radiation area.
Meanwhile, there could be a compact center object in the Crab Nebula, from which
X-rays are emitted.