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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en-AU">
<head>
<title>DSO Information</title>
<meta http-equiv="content-type" content="application/xhtml; charset=UTF-8" />
<link rel="stylesheet" type="text/css" href="style.css" media="screen, print, projection" />
</head>
<body>
<!--HEADER/LOGO-->
<div id="header">
<div id="logo">
<h1 id="TOP">DSO Information</h1>
</div>
<!--TAB NAVIGATION-->
<div id="topnav">
<a href="index.html" class="active">Information</a><!--Use class="active" to show where user is-->
<a href="object.html">Object Type</a>
<a href="distance.html">Distances</a>
<a href="images.html">Images</a>
<a href="screenshots.html">Screenshots</a>
</div>
</div>
<!--MAIN CONTENT-->
<div id="page-wrap">
<div id="content">
<div class="link">
<a href="#TOP">Top</a><br/>
<a href="#RCW">RCW 103</a><br/>
<a href="#IC4">IC 443</a><br/>
<a href="#ALP">Alpha Orionis</a><br/>
<a href="#HR5">HR 5171 A</a><br/>
<a href="#SNW">SN W49B</a><br/>
<a href="#ASS">ASSASN-15lh</a><br/>
<a href="#AGC">AG Carinae</a><br/>
<a href="#SDO">S Doradus</a><br/>
<a href="#SN1">SN 1987A</a><br/>
<a href="#GEM">Geminga</a><br/>
<a href="#NGC6">NGC 6357</a><br/>
<a href="#NGC7">NGC 7822</a><br/>
<a href="#M82">M82 X-2</a><br/>
<a href="#PSR">PSR B0355+54</a><br/>
<a href="#DEM">DEM L241</a><br/>
<a href="#CIR">Circinus X-1</a>
</div>
<h2 id="RCW">RCW 103</h2>
<h4>Properties:</h4>
<ul>
<li>Supernova Remnant with X-Ray Source 1E 161348-5055 at its heart</li>
<li>Constellation: Norma</li>
<li>Right Ascension: 16h17m30s</li>
<li>Declination: -51° 02′</li>
<li>Distance 3,100-3,300 pc</li>
<li>Radial Velocity: -48 km/s</li>
<li>Diameter: 75 ly</li>
<li>Angular Diameter: 10'</li>
<li>Age: 2,000 years</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>X-Ray source pulasar 1E 161348-5055 has led to investigations on periodicity
<ul>
<li>Discovered by the Einstein Observatory</li>
<li>Period of 6.67 hours, making it the slowest rotating pulsar known</li>
<li>The light curve can be quantitatively accounted for by models of propeller torques of both Illarionov-Sunyaev type and Romanova-Lovelace</li>
<li>1-300 GeV spectrum and the total flux gives a luminosity of 8.3 × 1033 erg s–1 at a source distance of 3.3 kpc</li>
<li>May have a magnetar nature</li>
<li>Two magnetars may have passive fallback disks, this one and 4U 0142+61</li>
<li>When the disk mass is high and the surface dipole field of the magnetar is as high as 4 × 10(15) G, the magnetar will evolve from the ejector phase to the propeller phase</li>
</ul>
</li>
<li>Pulsar flared and became 50 times brighter between October 1999 and January 2000</li>
<li>One explanation for slow period is an unseen binary partner, making it a low mass x-ray binary
<ul>
<li>Interaction of magnetic fields causes it to slow down</li>
<li>Explains flare, since mass could have transferred from partner</li>
<li>Could have double accretion process, where it is capturing material directly from companion and into an accretion disk</li>
</ul>
</li>
<li>Another explanation for slow period is that magnetic fields interacted with debris from original supernova</li>
<li>On June 22, 2016 the Swift telescope detected a short x-ray burst
<ul>
<li>Has intense x-ray fluctuations on the millisecond scale</li>
<li>Similar to other magnetars</li>
<li>Binary star explanation is unlikely because the x-ray fluctuations is highly irregular in energy and time</li>
</ul>
</li>
<li>There is a Fermi γ-ray counterpart to RCW 103</li>
</ul>
<br />
<h2 id="IC4">IC 443</h2>
<h4>Properties:</h4>
<ul>
<li>Supernova Remnant</li>
<li>Also Known as:
<ul>
<li>Jellyfish Nebula</li>
<li>PGC 2817561</li>
<li>SNR G189.0+03.0</li>
</ul>
</li>
<li>Constellation: Gemini</li>
<li>Right Ascension: 06h 17m 13s</li>
<li>Declination: +22° 31′ 05′′</li>
<li>Distance 5,000 ly</li>
<li>Angular Diameter: 50'</li>
<li>Spectral Class: SN II</li>
<li>Galaxy: Milky Way</li>
<li>Age: 3,000-30,000 years</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>Supernova likely created the neutron star CXOU J061705.3+222127, the collapsed remnant of the stellar core</li>
<li>Roughly 70 ly across
<ul>
<li>two subshells</li>
</ul>
</li>
<li>x-ray radiation is not dominated by pulsar wind nebula (aka plerion nebula) and also has thermal origin
<ul>
<li>mixed morphology SNR</li>
</ul>
</li>
<li>Nebula has a plerionic nature</li>
<li>Displays a centrally-peaked morphology, its brightness peaks being associated with hot (kT > 1 keV) X-ray emitting plasma</li>
<li>Strong emission lines of Mg, Si, and S, requiring oversolar metal abundances</li>
<li>X-ray source 1SAX J0618.0+2227, the brightest in this region</li>
<li>emission is greatly absorbed by molecular cloud around it</li>
</ul>
<br />
<h2 id="ALP">Alpha Orionis</h2>
<h4>Properties:</h4>
<ul>
<li>M1-M2 1b Star (Red Supergiant)</li>
<li>Also Known as:
<ul>
<li>Betelgeuse</li>
</ul>
</li>
<li>Constellation: Orion</li>
<li>Right Ascension: 05h 55m 10.30536s</li>
<li>Declination: +07° 24′ 25.4304″</li>
<li>Distance 222 pc</li>
<li>Apparent Magnitude: 0-1.3</li>
<li>Proper motion:
<ul>
<li>RA: 27.54 mas/yr</li>
<li>Dec: 11.30 mas/yr</li>
</ul>
</li>
<li>Radial Velocity: 21.91 km/s</li>
<li>Spin Rate: 15 km/s</li>
<li>Mass: 12-17 sm</li>
<li>Temperature: 3600K</li>
<li>Radius: 1180 sr</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>Ninth brightest star in the sky, second brightest in Orion</li>
<li>will explode in the next 100,000 years</li>
<li>classified as SRc variable
<ul>
<li>semiregular, low amplitude and occasional standstill</li>
</ul>
</li>
<li>nebula 400 AU across surrounds the star
<ul>
<li>formed from huge plumes of gas and dust thrown off by Betelgeuse because of vigorous convection at its surface</li>
<li>plumes are very uneven</li>
</ul>
</li>
<li>surrounded by several shells of gas and dust
<ul>
<li>650 AU, 12,000 AU, 36,000 AU, 1pc</li>
</ul>
</li>
<li>formed as a member of the Orion OB1 association</li>
<li>One of the largest and luminous stars visible to the naked eye, if it took the place of the sun it would extend past the asteroid belt.</li>
<li>Has extended atmosphere, and strong molecular bands whidh do not originate in the photosphere, but in a cooler layer above it</li>
<li>Has a very low density water layer close above the photosphere</li>
<li>May have amorphous alumina dust</li>
<li>surface has very uneven temperature
<ul>
<li>HST discovered bright spot 10 times the diameter of earth which was 2000K hotter than its surroundings</li>
</ul>
</li>
</ul>
<br />
<h2 id="HR5">HR 5171 A</h2>
<h4>Properties:</h4>
<ul>
<li>Star (Yellow Hypergiant) in 3 star system</li>
<li>Also Known as:
<ul>
<li>V766 Centauri</li>
</ul>
</li>
<li>Constellation: Centaurus</li>
<li>Spectral Type: G8Ia</li>
<li>Right Ascension: 13h 47m 10.875s</li>
<li>Declination: −62° 35′ 23.06″</li>
<li>Proper motion:
<ul>
<li>RA: -2.94 mas/yr</li>
<li>Dec: -2.54 mas/yr</li>
</ul>
</li>
<li>Radial Velocity: -38.2 km/s</li>
<li>Mass: 30 sm</li>
<li>Temperature: 5000K</li>
<li>Radius: 1,300 sr</li>
<li>Distance 11,700 ly</li>
<li>Luminosity: 630,000 sl</li>
<li>Period: 1300 days</li>
<li>Inclination: 60</li>
<li>Absolute Magnitude: -9.2</li>
<li>Apparent Magnitude: 9.83</li>
<li>Age: 3.5-4 Million Years</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>One of the largest known stars (R = 1315 ± 260 sr)</li>
<li>Has companion star with period 1,304 days</li>
<li>Companion is 1/3 the size of the star</li>
<li>has contact binary partner
<ul>
<li>eclipsing binary system</li>
<li>undergoing roche lobe overflow</li>
<li>partner is about 5000K</li>
</ul>
</li>
<li>has been growing and cooling over the past 40 years</li>
<li>blue light near star is from polycyclic aromatic hydrocarbons</li>
<li>HgMn Star</li>
<li>Presence of lines from the rare-earth spectra Nd III and Pr III, and the heavy elements Pt, Au, Hg, Tl, and Bi</li>
<li>Hg I and Hg II, and three lines of Pt II were also seen</li>
<li>Large level of asymmetry in the brightness distribution of the system, due to companion star located in front of the primary star</li>
<li>System is probably experiencing a wind Roche-Lobe overflow</li>
<li>May become a fast-rotating B[e]/luminous blue variable/Wolf-Rayet star</li>
</ul>
<br />
<h2 id="SNW">SN W49B</h2>
<h4>Properties:</h4>
<ul>
<li>Supernova Remnant in Westerhout 49</li>
<li>Also Known as:
<ul>
<li>SNR G043.3-00.2</li>
<li>3C 398</li>
</ul>
</li>
<li>Constellation: Aquila</li>
<li>Right Ascension: 19h 11m 09s</li>
<li>Declination: +09° 06′ 24″</li>
<li>Distance 37,000 ly</li>
<li>Age: 1,000 Years</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>originated from a type 1b or 1c supernova
<ul>
<li>may have produced GRB</li>
<li>probably black hole remnant since no neutron star is visible</li>
</ul>
</li>
<li>one of the most luminous SNRs in gamma rays
<ul>
<li>invisible in optical</li>
</ul>
</li>
<li>x-ray emission is from forbidden transitions in iron and nickel
<ul>
<li>also shows x-ray emission from chromium and manganese</li>
<li>iron is only in western half of nebula</li>
</ul>
</li>
<li>inner barrel shaped shell is 60 ly in diameter
<ul>
<li>asymmetric explosion</li>
<li>temperature of 15 million K</li>
</ul>
</li>
<li>outer shell is 10 pc across and 1.9 pc thick
<ul>
<li>contains x-ray jets and a bow shock where the SE jet meets the shell</li>
</ul>
</li>
<li>Instead of radiating out symmetrically, W49B's exploding star shot more material out from its poles versus from its equator.</li>
<li>There is evidence that W49B left behind a black hole - not a neutron star like most other supernovas.</li>
<li>If confirmed, W49B would be the most recent black hole formed in our Galaxy.</li>
<li>The structure of the circumstellar medium affect the metal distribution and composition of the SNR</li>
<li>SN triggered by the collapse of a 25 M (☉) Wolf-Rayet star</li>
<li>Model of bipolar/jet-driven core-collapse SNe</li>
<li>Large level of asymmetry in the brightness distribution of the system, due to companion star located in front of the primary star</li>
<li>W49B is indicative of a bipolar Type Ib/Ic SN origin, making it the first of its kind to be discovered in the Milky Way.</li>
<li>The following sequence of events has been suggested to account for the X-ray and infrared data: A massive star formed from a dense cloud of dust and gas, shone brightly for a few million years while spinning off rings of gas and pushing them away to form a nearly empty cavity around the star. The star then exhausted its nuclear fuel and its core collapsed to form a black hole. Much of the gas around the black hole was pulled into it, but some, including material rich in iron and nickel was flung away in oppositely directed jets of gas traveling near the speed of light. When the jet hit the dense cloud surrounding the star, it flared out and drove a shock wave into the cloud.
An observer aligned with one these jets would have seen a gamma-ray burst, a blinding flash in which the concentrated power equals that of ten quadrillion Suns for a minute or so. The view perpendicular to the jets would be a less astonishing, although nonetheless spectacular supernova explosion. For W49B, the jet is tilted out of the plane of the sky by about 20 degrees, but the remains of the jet are visible as a hot X-ray emitting bar of gas.</li>
</ul>
<br />
<h2 id="ASS">ASSASN-15lh</h2>
<h4>Properties:</h4>
<ul>
<li>Supernova Remnant</li>
<li>Also Known as:
<ul>
<li>SN 2015L</li>
</ul>
</li>
<li>Constellation: Indus</li>
<li>Galaxy: APMUKS(BJ) B215839.70−615403.9</li>
<li>Right Ascension: 22h 2m 15.45s</li>
<li>Declination: −61° 39′ 34.64″</li>
<li>Distance 1,171 Mpc</li>
<li>Peak Apparent Magnitude: 16.9</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>Brightest supernova-like object ever observed, by All Sky Automated Survey for SuperNovae on June 14 2015</li>
<li>at peak, had apparent magnitude of 16.9 and was 570 billion times brighter than sun
<ul>
<li>temperature was 20,000K and radius was 70,000 sr</li>
</ul>
</li>
<li>brightness peaked on June 5th, there was a rebrightening 90 days after peak and bolometric luminosity plateaued for 120 days</li>
<li>total energy emitted over first 50 days was around 1.1e45 Joules</li>
<li>no hydrogen or helium lines in spectrum</li>
<li>most popular explanation is that it was supermassive black hole breaking apart a star due to tidal forces
<ul>
<li>called a tidal disruption event</li>
<li>requires rapidly spinning kerr black hole</li>
</ul>
</li>
<li>other explanations include that it was:
<ul>
<li>a hypernova (SLSNe)
<ul>
<li>approaches theoretical limits, and double-peaked spectrum does not match models</li>
</ul>
</li>
<li>spindown of magnetar
<ul>
<li>approaches theoretical limits, and some properties are hard to explain</li>
</ul>
</li>
<li>quark nova
<ul>
<li>explains many features but not known to actually exist</li>
</ul>
</li>
</ul>
</li>
<li>Nature is disputed, could be most luminous type I supernova (hypernova) ever discovered or a tidal disruption event around a supermassive black hole</li>
<li>Explosion was only mildly asymmetric</li>
<li>Flux of ASASSN-15lh to increase strongly into the ultraviolet, with an ultraviolet luminosity 100 times greater than the hydrogen-rich, ultraviolet-bright SLSN II SN 2008es.</li>
<li>Spectra show no strong hydrogen emission</li>
<li>Has Tidal Disruption Flares, which is consistent with the black hole theory</li>
</ul>
<br />
<h2 id="AGC">AG Carinae</h2>
<h4>Properties:</h4>
<ul>
<li>Luminous Blue Variable Star</li>
<li>Also Known as:
<ul>
<li>CD–59°3430</li>
<li>HD 94910</li>
</ul>
</li>
<li>Constellation: Carina</li>
<li>Right Ascension: 10h 56m 11.57699s</li>
<li>Declination: −60° 27′ 12.8056″</li>
<li>Proper Motion:
<ul>
<li>RA: -4.86 mas/yr</li>
<li>Dec: 1.92 mas/yr</li>
</ul>
</li>
<li>Radial Velocity: -54 km/s</li>
<li>Distance 6,000 pc</li>
<li>Mass: 55 sm</li>
<li>Radius: 65-400 sr</li>
<li>Temperature: 8000-24,000K</li>
<li>Luminosity: 1e6-1.5e6 sl</li>
<li>Apparent Magnitude: varies erratically between 5.7-9.0</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>One of the most luminous stars in the Milky Way galaxy</li>
<li>star is surrounded by a nebula from 0.4 to 1.2 pc around the star
<ul>
<li>contains 15 sm lost around 10,000 years ago</li>
<li>expanding at 50 km/s</li>
</ul>
</li>
<li>past the nebula there is an 8.8 pc wide cavity in the ISM
<ul>
<li>cleared away by fast winds early in the star’s life</li>
</ul>
</li>
<li>transitioning between class O supergiant and WR star</li>
<li>at minimum brightness, its temperature is 8000K and its radius is 400 sr</li>
<li>at maximum brightness, its temperature is 20,000-24,000K and its radius is 65 sr</li>
<li>bolometric luminosity actually decreases when brightness increases
<ul>
<li>because of energy expended to expand star</li>
</ul>
</li>
<li>stellar winds are 1945 km/s</li>
<li>1985-1990 (Teff= 22,800 K) and 2000-2001 (Teff=17,000 K) shows Teff change placing it on different sides of the bistability limit</li>
<li>220 +- 50 km/s during 1985-1990 which, combined with the high luminosity (L=1.5x10^6 Lsun), puts AG Car extremely close to the Eddington limit</li>
<li>Inclination angle of 90 degrees</li>
<li>Initial mass of ~ 100 Msun and a current mass of 60-70 Msun, close to, if not at, the Omega-Gamma limit</li>
<li>Detection of broad absorptions due to Si IV λλ4088-4116</li>
<li>Rotational velocity of 190 ± 30 km s-1 in 2001 April</li>
</ul>
<br />
<h2 id="SDO">S Doradus</h2>
<h4>Properties:</h4>
<ul>
<li>Luminous Blue Variable Star in Large Magellanic Cloud</li>
<li>Also Known as:
<ul>
<li>CD-69 295</li>
<li>HD 35343</li>
</ul>
</li>
<li>Constellation: Dorado</li>
<li>Right Ascension: 05h 18m 14.3550s</li>
<li>Declination: −69° 15′ 01.151″</li>
<li>Distance 169,000 ly</li>
<li>Apparent Magnitude: 8.6-11.5</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>One of the most luminous stars in the LMC, but too far away to see with naked eye</li>
<li>Secchi type I with bright lines of Hα, Hβ, and Hγ.</li>
<li>Member of the open cluster NGC 1910, has a number of close companion stars</li>
<li>The colour of S Doradus changes as its brightness varies, being bluest when the star is faintest</li>
<li>On S Doradus Instability Strip</li>
<li>The temperature was calculated to drop from 20,000 K to 9,000 K, and the luminosity dropped from 1,400,000 L☉ to 708,000 L☉. In 1989</li>
</ul>
<br />
<h2 id="SN1">SN 1987A</h2>
<h4>Properties:</h4>
<ul>
<li>Supernova on outskirts of the Tarantula Nebula in the Large Magellanic Cloud</li>
<li>Also Known as:
<ul>
<li>AAVSO 0534-69</li>
</ul>
</li>
<li>Constellation: Dorado</li>
<li>Right Ascension: 05h 35m 28.03s</li>
<li>Declination: −69° 16′ 11.79″</li>
<li>Distance 168,000 ly</li>
<li>Peak Apparent Magnitude: 2.9</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>Brightness peaked in May of 1987 and declined from then on</li>
<li>Very broad (v-b) lines with a full width at half-maximum (FWHM) of order 104 km s–1</li>
<li>The blast wave (BW) was primarily interacting with the H II region around the progenitor</li>
<li>The interaction with H II region material is ongoing</li>
<li>The interaction with the H II region (ρinit ≈ 130 amu cm–3, ± 15° opening angle) produces the very broad emission lines and most of the 3-10 keV flux</li>
<li>Observed through light-radiation window</li>
<li>We propose an asymmetric two-sided distribution of 56Ni most dominant in the southern far quadrant of SN 1987A as the most probable explanation of the observed light echo spectra.</li>
<li>The asymmetry of high-velocity 56Ni in the first few hundred days after explosion is correlated to the geometry of the ejecta some 25 years later.</li>
</ul>
<br />
<h2 id="GEM">Geminga</h2>
<h4>Properties:</h4>
<ul>
<li>Neutron Star and Gamma Ray Source</li>
<li>name is abbreviation for “Gemini gamma ray source
<ul>
<li>also means “does not exist” in Milanese dialect</li>
</ul>
</li>
<li>Also Known as:
<ul>
<li>SN 437</li>
<li>PSR B0633+17</li>
</ul>
</li>
<li>Constellation: Gemini</li>
<li>Right Ascension: 06h 33m 54.15s</li>
<li>Declination: +17° 46′ 12.9″</li>
<li>Distance 800 ly from Sun</li>
<li>Period: 0.237 s</li>
<li>Proper Motion: 178.2 mas/yr</li>
<li>Peak Apparent Magnitude: 25.5</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>second brightest high energy gamma ray source
<ul>
<li>closest known pulsar to earth</li>
</ul>
</li>
<li>only known radio-quiet pulsar
<ul>
<li>likely because its beams of radiation don’t pass through earth</li>
</ul>
</li>
<li>supernova took place 300,000 years ago
<ul>
<li>partly responsible for clearing local bubble</li>
</ul>
</li>
<li>discovered in 1972 by SAS-2 satellite</li>
<li>in 1991 periodicity was discovered by ROSAT</li>
<li>Discovered by Giovanni Bignami</li>
<li>Potential origins of the positron excess above 10 GeV</li>
<li>timing variations detected by COS-B and EGRET showed that it might have a planet
<ul>
<li>could just be noise in measurement</li>
</ul>
</li>
<li>moving through space at 205 km/s</li>
<li>The fastest change occurred in the circumstellar environment at a rate of 80 per cent of the speed of light</li>
<li>One of the most spectacular results is the wiggling of a half light-year long tail as an extension of the jet, which is significantly bent by the ram pressure</li>
<li>The jet wiggling occurred at a rate of about 20 per cent of the speed of light</li>
<li>The slope of the far-ultraviolet (FUV) spectrum is close to that of a Rayleigh-Jeans spectrum, suggesting that the FUV radiation is dominated by thermal emission from the neutron star (NS) surface.</li>
</ul>
<br />
<h2 id="NGC6">NGC 6357</h2>
<h4>Properties:</h4>
<ul>
<li>Diffuse Nebula</li>
<li>Also Known as:
<ul>
<li>Lobster Nebula</li>
<li>War and Peace Nebula</li>
<li>Sharpless 11</li>
<li>RCW 131</li>
<li>Gum 66</li>
</ul>
</li>
<li>Constellation: Scorpius</li>
<li>Right Ascension: 17h 24m</li>
<li>Declination: −34° 20′</li>
<li>Distance 8,000 ly</li>
<li>Diameter: 80 ly</li>
<li>Proper Motion:
<ul>
<li>RA: -1.99 mas/yr</li>
<li>Dec: -2.41 mas/yr</li>
</ul>
</li>
<li>Radial Velocity: -8 km/s</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>Contains clusters, Pismis24, G353.2+0.7, G353.1+0.36</li>
<li>contains many protostars shielded by cocoons</li>
<li>clusters G353.2+0.7 and GG353.1+0.36 have around 800 stars each</li>
<li>open cluster Pismis 24 has some of the most massive stars known
<ul>
<li>Pismis 24-1 is a system of three stars with mass 200-300 sm</li>
<li>two stars are optically resolvable, one of those is a spectroscopic binary</li>
<li>Pismis 24-17 is around 100 sm</li>
</ul>
</li>
<li>Candidate X-ray emitting star</li>
<li>Median age of 1 Myr for the Pismis 24 cluster members</li>
<li>NGC 6357's total cluster population is a few times the known Orion population</li>
<li>Many cluster members are estimated to be intermediate-mass stars from available infrared photometry</li>
<li>The slope of the far-ultraviolet (FUV) spectrum is close to that of a Rayleigh-Jeans spectrum, suggesting that the FUV radiation is dominated by thermal emission from the neutron star (NS) surface.</li>
</ul>
<br />
<h2 id="NGC7">NGC 7822</h2>
<h4>Properties:</h4>
<ul>
<li>Young Star Forming Complex</li>
<li>Also Known as:
<ul>
<li>LBN 589</li>
<li>Sh 2-171</li>
</ul>
</li>
<li>Constellation: Cepheus</li>
<li>Right Ascension: 00h 01m 08.58s</li>
<li>Declination: +67° 25′ 17.0″</li>
<li>Distance 2,900 ly</li>
<li>Diameter: 300 ly</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>Contains emission region Sharpless 171 and cluster Berkeley 59</li>
<li>Complex contains one of the hottest star, BD+66 1673, within 1 Kpc of the sun, which is also an eclipsing binary</li>
<li>has temperature of 45000K and around 100,000 times sun’s luminosity</li>
<li>Creates "elephant trunks" or pillars of formation
<ul>
<li>Trunks rotate as rigid bodies (to a first approximation) about their major axes</li>
<li>Rotational periods are of the order of a few million years – similar to the age of the clusters. </li>
<li> The trunks carry surprisingly large amounts of angular momentum, kg m2 s-1, with corresponding rotational energies of up to ~1037 J</li>
</ul>
</li>
</ul>
<br />
<h2 id="M82">M82 X-2</h2>
<h4>Properties:</h4>
<ul>
<li>X-Ray Pulsar in Messier 82, the cigar galaxy, in binary system</li>
<li>Also Known as:
<ul>
<li>J095550.9+694044</li>
<li>J095551+6940.8</li>
</ul>
</li>
<li>Constellation: Ursa Major</li>
<li>Right Ascension: 09h 55m 51.0s</li>
<li>Declination: 69° 40′ 45″</li>
<li>Distance 12 million ly</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>Very luminous, radiating energy equivalent to ten million Suns</li>
<li>Has average size 1.4 sm and has a companion which is 5.2 sm</li>
<li>Rotates every 1.37 seconds, and revolves around its companion every 2.5 days</li>
<li>long term pattern changes over weeks or months</li>
<li>ultraluminous x-ray source (ULX)
<ul>
<li>luminosity 100x greater than eddingtom limit</li>
</ul>
</li>
<li>binary system
<ul>
<li>if the pulsar weighs 1.4 sm, companion is 5.2 sm</li>
</ul>
</li>
<li>We find that the derived neutron star's dipole magnetic field depends the maximum accretion rate adopted, but is likely less than 10^13 G</li>
<li>Its isotropic X-ray luminosity L_iso = 1.8 × 10^40 erg s^− 1 during outbursts is 100 times the Eddington limit for a 1.4 M_⊙ neutron star</li>
<li>The accretion rate at the magnetospheric radius must be super-Eddington during outbursts</li>
<li>the binary system that formed M82 X-2 is most likely less than 50 Myr old and contains a donor star which had an initial mass of approximately 8–10 sm</li>
<li>We attribute the excess iron line emission to the ULX in its high state. In general, the iron K-shell luminosity of M82 is dominated by the diffuse component.</li>
<li>In the M82 Galaxy, the three star clusters will eventually merge</li>
<li>Luminosities of ultraluminous X-ray sources (ULXs) are large when compared to the Eddington limit for isotropic accretion onto stellar-mass object. However, the recent discovery of coherent pulsations from ULX M82 X-1 has shown that another scenario implying accretion onto a magnetized neutron star is possible for ULXs. We have found no evidence for significant coherent pulsations in any of the sources including the M82 X-2.</li>
</ul>
<br />
<h2 id="PSR">PSR B0355+54</h2>
<h4>Properties:</h4>
<ul>
<li>X-Ray Pulsar in Messier 82, in binary system</li>
<li>Also Known as:
<ul>
<li>NVSS J033259+543444</li>
</ul>
</li>
<li>Constellation: Camelopardalis</li>
<li>Right Ascension: 03h 32m 59.368s</li>
<li>Declination: +54° 34′ 43.57″</li>
<li>Distance 3.46 kly</li>
<li>Age: 500,000 yr</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>Completes one rotation every .71452 seconds</li>
<li>one of the brightest radio pulsar not detected in gamma rays</li>
<li>jets are pointing straight at us</li>
<li>trail from jet extends almost 5 ly because it is moving so fast</li>
<li>Announced two extrasolar planets orbiting the pulsar, but observations ruled out this idea</li>
<li>Suggests a small angle between the pulsar spin axis and our line of sight, as inferred from the radio data</li>
<li>On larger scales, emission from the 7′7′ (≈2≈2 pc) tail is clearly seen, two faint extensions nearly orthogonal to the direction of the pulsar’s proper motion is also seen</li>
<li>Surprisingly, the spectrum of the tail shows only a slight hint of cooling with increasing distance from the pulsar. This implies either a low magnetic field with fast flow speed, or particle reacceleration within the tail</li>
<li>The density profile found for PSR B0355+54 shows a perfect exponential decrease towards the tube edge.</li>
</ul>
<br />
<h2 id="DEM">DEM L241</h2>
<h4>Properties:</h4>
<ul>
<li>Supernova Remnant in Large Magallenic Cloud</li>
<li>Constellation: Dorado</li>
<li>Right Ascension: 05h 36m 00.00s</li>
<li>Declination: -67° 35' 09.00"</li>
<li>Distance 160,000 ly</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>Evidence of star which survived the blast</li>
<li>Cloud supernova remnant DEM L241 reveals an interior unresolved source which is probably an accretion-powered binary.</li>
<li>A High-Mass X-ray Binary (HMXB) with orbital period likely to be of order tens of days associated with a massive O5III star</li>
<li>Elongation of the remnant is unusual</li>
<li>The precursor star probably had mass > 25 solar masses</li>
<li>Optical radial velocity measurements suggest that the system contains a neutron star.</li>
<li>The source is significantly more luminous than similar sources in the Milky Way, at radio, optical, X-ray, and gamma-ray wavelengths</li>
<li>HII region contains SNR</li>
<li>companion star remains inside SNR and is in orbit with the black hole or neutron star</li>
<li>SNR spectrum has oxygen, neon and magnesium indicating progenitor was 25-40 sm</li>
<li>HII regions formed by radiation from the binary system</li>
<li>remaining star will itself explode in a couple million years</li>
</ul>
<br />
<h2 id="CIR">Circinus X-1</h2>
<h4>Properties:</h4>
<ul>
<li>X-Ray binary star system that includes a neutron star</li>
<li>Also Known as:
<ul>
<li>INTREF 645</li>
</ul>
</li>
<li>Constellation: Circinus</li>
<li>Right Ascension: 15h 20m 40.85s</li>
<li>Declination: −57° 10′ 00.1″</li>
<li>Apparent Magnitude: 21.40</li>
<li>Distance 31,000 ly</li>
<li>Orbit:
<ul>
<li>Period: 16.7 d</li>
<li>Eccentricity: 0.45</li>
</ul>
</li>
</ul>
<h4>Characteristics:</h4>
<ul>
<li>There is a presence of X-ray jets normally found in black hole systems</li>
<li>contains a neutron star orbiting main sequence star slightly more massive than sun
<ul>
<li>x-rays are from accretion disk around neutron star</li>
</ul>
</li>
<li>P Cygni profile shows that accretion disk is blasting gas out at 2000 km/s
<ul>
<li>seen in Si IV emission line</li>
</ul>
</li>
<li>The optical light curve of Cir X-1 is strongly variable, changing in brightness by 1.2 magnitudes in the space of four days.</li>
<li>Among the youngest X-ray binaries observed, 2,600 years old possibly</li>
<li>We detect strong, variable H-alpha emission lines, consisting of multiple components which vary with orbital phase</li>
<li>We suggest that the companion star is over-luminous and under-dense, due to the impact of the supernova which occurred less than 5000 yr ago.</li>
<li>Observations with Chandra and XMM-Newton from 40 to 80 days after the flare reveal a bright X-ray light echo in the form of four well-defined rings with radii from 5 to 13 arcmin, growing in radius with time.</li>
<li>The two innermost rings with clouds at radial velocity -74 and -81 kms^-1, respectively</li>
<li>From the association of the rings with individual CO clouds we determine the kinematic distance to Circinus X-1 to be D = 9.4kpc. This distance rules out earlier claims of a distance around 4 kpc, implies that Circinus X-1 is a frequent super-Eddington source</li>
<li>The magnetic field of the neutron star is small</li>
<li>Circinus X-1 is a microquasar, creating relativistic jets that were thought to power the arcminute-scale radio nebula surrounding the source.</li>
<li>Spectrum dominated by emission from H i, He i and low-excitation metals</li>
</ul>
<br/>
</div>
</div>
</div>
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