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Start Over Subject nebulae Content Level Research
111. Wide Field Planetary Camera 2
ID:
ivo://archive.stsci.edu/hst/wfpc2
Title:
Wide Field Planetary Camera 2
Short Name:
HST.WFPC2
Date:
23 Jul 2020 19:52:01
Publisher:
Space Telescope Science Institute Archive
Description:
The WFPC2 is used to obtain high resolution images of astronomical objects over a relatively wide field of view and a broad range of wavelengths (1150 to 11,000 Å).
112. Wide Field Planetary Camera 1
ID:
ivo://archive.stsci.edu/hst/wfpc1
Title:
Wide Field Planetary Camera 1
Short Name:
HST.WFPC1
Date:
23 Jul 2020 19:51:30
Publisher:
Space Telescope Science Institute Archive
Description:
The WF/PC-1 was used from April 1990 to November 1993, to obtain high resolution images of astronomical objects over a relatively wide field of view and a broad range of wavelengths (1150 to 11,000 Angstroms).
113. XMM-Newton brightest serendipitous sources
ID:
ivo://CDS.VizieR/J/ApJ/819/40
Title:
XMM-Newton brightest serendipitous sources
Short Name:
J/ApJ/819/40
Date:
21 Oct 2021
Publisher:
CDS
Description:
We analyzed a deep XMM-Newton observation of the radio-quiet {gamma}-ray PSR J2055+2539. The spectrum of the X-ray counterpart is nonthermal, with a photon index of {Gamma}=2.36+/-0.14 (1{sigma} confidence). We detected X-ray pulsations with a pulsed fraction of 25%+/-3% and a sinusoidal shape. Taking into account considerations on the {gamma}-ray efficiency of the pulsar and on its X-ray spectrum, we can infer a pulsar distance ranging from 450 to 750 pc. We found two different nebular features associated with PSR J2055+2539 and protruding from it. The angle between the two nebular main axes is ~162.8{deg}+/-0.7{deg}. The main, brighter feature is 12' long and <20" thick, characterized by an asymmetry with respect to the main axis that evolves with the distance from the pulsar, possibly forming a helical pattern. The secondary feature is 250"x30". Both nebulae present an almost flat brightness profile with a sudden decrease at the end. The nebulae can be fitted by either a power-law model or a thermal bremsstrahlung model. A plausible interpretation of the brighter nebula is in terms of a collimated ballistic jet. The secondary nebula is most likely a classical synchrotron-emitting tail.
114. X-ray survey of NGC7000/IC5070
ID:
ivo://CDS.VizieR/J/A+A/602/A115
Title:
X-ray survey of NGC7000/IC5070
Short Name:
J/A+A/602/A115
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first extensive X-ray study of the North-America and Pelican star-forming region (NGC7000/IC5070), with the aim of finding and characterizing the young population of this cloud. X-ray data from Chandra (four pointings) and XMM-Newton (seven pointings) were reduced and source detection algorithm applied to each image. We complement the X-ray data with optical and near-IR data from the IPHAS, UKIDSS, and 2MASS catalogs, and with other published optical and Spitzer IR data. More than 700 X-ray sources are detected, the majority of which have an optical or NIR counterpart. This allowed us to identify young stars in different stages of formation. Less than 30% of X-ray sources are identified with a previously known young star. We argue that most X-ray sources with an optical or NIR counterpart, except perhaps for a few tens at near-zero reddening, are likely candidate members of the star-forming region, on the basis of both their optical and NIR magnitudes and colors, and of X-ray properties such as spectrum hardness or flux variations. They are characterized by a wide range of extinction, and sometimes near-IR excesses, both of which prevent derivation of accurate stellar parameters. The optical color-magnitude diagram suggests ages between 1-10Myrs. The X-ray members have a very complex spatial distribution with some degree of subclustering, qualitatively similar to that of previously known members. The detailed distribution of X-ray sources relative to the objects with IR excesses identified with Spitzer is sometimes suggestive of sequential star formation, especially near the 'Gulf of Mexico' region, probably triggered by the O5 star which illuminates the whole region. We confirm that around the O5 star no enhancement in the young star density is found, in agreement with previous results. Thanks to the precision and depth of the IPHAS and UKIDSS data used, we also determine the local optical-IR reddening law, and compute an updated reddening map of the entire region.