Arp 147 in 60 Seconds (High Definition)

  • Arp 147 contains a spiral galaxy (right) that collided with an elliptical galaxy (left), triggering a wave of star formation.
  • Many of these newly-born massive stars raced through their lives and ended with supernova explosions, some as black holes.
  • A ring of these black holes can be seen in the Chandra data (pink) around the spiral galaxy.

Just in time for Valentine’s Day comes a new image of a ring — not of jewels — but of black holes. This composite image of Arp 147, a pair of interacting galaxies located about 430 million light years from Earth, shows X-rays from the NASA’s Chandra X-ray Observatory (pink) and optical data from the Hubble Space Telescope (red, green, blue) produced by the Space Telescope Science Institute (STScI) in Baltimore, Md.

Arp 147 contains the remnant of a spiral galaxy (right) that collided with the elliptical galaxy on the left. This collision has produced an expanding wave of star formation that shows up as a blue ring containing in abundance of massive young stars. These stars race through their evolution in a few million years or less and explode as supernovas, leaving behind neutron stars and black holes.

A fraction of the neutron stars and black holes will have companion stars, and may become bright X-ray sources as they pull in matter from their companions. The nine X-ray sources scattered around the ring in Arp 147 are so bright that they must be black holes, with masses that are likely ten to twenty times that of the Sun.

An X-ray source is also detected in the nucleus of the red galaxy on the left and may be powered by a poorly-fed supermassive black hole. This source is not obvious in the composite image but can easily be seen in the X-ray image. Other objects unrelated to Arp 147 are also visible: a foreground star in the lower left of the image and a background quasar as the pink source above and to the left of the red galaxy.

Infrared observations with NASA’s Spitzer Space Telescope and ultraviolet observations with NASA’s Galaxy Evolution Explorer (GALEX) have allowed estimates of the rate of star formation in the ring. These estimates, combined with the use of models for the evolution of binary stars have allowed the authors to conclude that the most intense star formation may have ended some 15 million years ago, in Earth’s time frame.

These results were published in the October 1st, 2010 issue of The Astrophysical Journal. The authors were Saul Rappaport and Alan Levine from the Massachusetts Institute of Technology, David Pooley from Eureka Scientific and Benjamin Steinhorn, also from MIT.

Fast Facts for Arp 147:
Credit X-ray: NASA/CXC/MIT/S.Rappaport et al, Optical: NASA/STScI
Scale Image is 54 arcsec across. (about 115,000 light years across)
Category Normal Galaxies & Starburst Galaxies
Coordinates (J2000) RA 03h 11m 18.9s | Dec +01° 18′ 52.99”
Constellation Cetus
Observation Date 9/13/2009, 9/15/2009
Observation Time 11 hours 49 min
Obs. ID 11280, 11887
Color Code Optical (Red, Green, Blue); X-ray (Magenta)
Instrument ACIS
Also Known As Ring Galaxy
Distance Estimate 440 million light years
Release Date February 9, 2011

Cassiopeia A in 60 Seconds (High Definition)

  • Evidence for a bizarre state of matter – known as a superfluid – has been found in Cassiopeia A.
  • Cassiopeia A (Cas A for short) is a supernova remnant located about 11,000 light years away from Earth.
  • Chandra observations taken over a decade show significant cooling in the dense core left behind after the explosion.

This composite image shows a beautiful X-ray and optical view of Cassiopeia A (Cas A), a supernova remnant located in our Galaxy about 11,000 light years away. These are the remains of a massive star that exploded about 330 years ago, as measured in Earth’s time frame. X-rays from Chandra are shown in red, green and blue along with optical data from Hubble in gold.

At the center of the image is a neutron star, an ultra-dense star created by the supernova. Ten years of observations with Chandra have revealed a 4% decline in the temperature of this neutron star, an unexpectedly rapid cooling. Two new papers by independent research teams show that this cooling is likely caused by a neutron superfluid forming in its central regions, the first direct evidence for this bizarre state of matter in the core of a neutron star.

The inset shows an artist’s impression of the neutron star at the center of Cas A. The different colored layers in the cutout region show the crust (orange), the core (red), where densities are much higher, and the part of the core where the neutrons are thought to be in a superfluid state (inner red ball). The blue rays emanating from the center of the star represent the copious numbers of neutrinos — nearly massless, weakly interacting particles — that are created as the core temperature falls below a critical level and a neutron superfluid is formed, a process that began about 100 years ago as observed from Earth. These neutrinos escape from the star, taking energy with them and causing the star to cool much more rapidly.

This new research has allowed the teams to place the first observational constraints on a range of properties of superfluid material in neutron stars. The critical temperature was constrained to between one half a billion to just under a billion degrees Celsius. A wide region of the neutron star is expected to be forming a neutron superfluid as observed now, and to fully explain the rapid cooling, the protons in the neutron star must have formed a superfluid even earlier after the explosion. Because they are charged particles, the protons also form a superconductor.

Using a model that has been constrained by the Chandra observations, the future behavior of the neutron star has been predicted. The rapid cooling is expected to continue for a few decades and then it should slow down.

Fast Facts for Cassiopeia A:
Credit X-ray: NASA/CXC/UNAM/Ioffe/D.Page,P.Shternin et al; Optical: NASA/STScI; Illustration: NASA/CXC/M.Weiss
Scale Image is 8.91 arcmin across (about 26 light years)
Category Supernovas & Supernova Remnants
Coordinates (J2000) RA 23h 23m 26.7s | Dec +58° 49′ 03.00″
Constellation Cassiopeia
Observation Date Nine observations in 2004: Feb 8, Apr 14, 18, 20, 22, 25 28, May 01, 05
Observation Time 278 hours
Obs. ID 4634-4639, 5196, 5319-5320
Color Code X-ray: Red 0.5-1.5 keV; Green 1.5-2.5; Blue 4.0-6.0, Optical: Gold
Instrument ACIS
Also Known As Cas A
References Page, D. et al., 2011, Phys.Rev.Lett. 106, 081101 (http://lanl.arxiv.org/abs/1011.6142) Shternin, P. et al. 2011, MNRAS, L206S (http://lanl.arxiv.org/abs/1012.0045)
Distance Estimate 11,000 light years
Release Date February 23, 2011

Tycho in 60 Seconds(High Definition)

Fast Facts for Tycho’s Supernova Remnant:
Credit NASA/CXC/Chinese Academy of Sciences/F. Lu et al
Scale Image is 10 arcmin across (about 38 light years)
Category Supernovas & Supernova Remnants
Coordinates (J2000) RA 00h 25m 17s | Dec +64° 08′ 37″
Constellation Cassiopeia
Observation Date 2 pointings between April 29, 2003 and May 3, 2009
Observation Time 283 hours
Obs. ID 3837, 7639, 8551, 10093-10097; 10902-10904; 10906
Color Code Energy: Red 1.6-2.0 keV, Green 2.2-2.6 keV, Blue 4-6 keV
Instrument ACIS
Also Known As G120.1+01.4, SN 1572
References Lu, F.J. et al, 2011, ApJ, 732:11
Distance Estimate About 13,000 light years
Release Date April 26, 2011

Pitica alba in formare


Aceasta imagine a Nebuloasei Helix ne arata o stea muribunda, fiind surprinsa tranzitia spre o pitica alba. Inelele colorate reprezinta gazele expulzate in in perioada de tranzitie, ca si cum si-ar da ultima suflare. Vederea acestei stele apropiata ca masa de soarele nostu, ne ofera un indiciu, despre cum ar putea soarele nostru sa arate intr-o buna zi, atunci cand va fi aproape de sfarsitul vietii sale. Sistemul se afla la aproximativ 650 ani-lumina in constelatia Varsatorului.

Imagine: NASA, WIYN, NOAO, ESA, Hubble Helix Nebula Team, M. Meixner (STScI), & T. A. Rector (NRAO)

Pitica alba care mananca comete


O pitica alba numita G29-38 pare ca mananca cometele orbitand in jurul ei, aparent lasand in urma doar un nor de praf, ramasite care au fost detectate de Spitzer Space Telescope al NASA. Descoperirea ofera prima dovada observationala a faptului ca unele comete ar putea trai mai mult de cat sorii lor. Oamenii de stiinta cred ca G29-38 a murit devenind o pitica alba acum 500 milioane de ani, inghitindu-si planetele interioare. Cometele, totusi, orbitand mult in afara zonei interioare, pot supravietui. Praful identificat de Spitzer, a fost creat atunci cand o cometa a fost prinsa in zona interioara a sistemului, si a fost pur si simplu pulverizata de fortele gravitationale imense.

Imagine : NASA/JPL-Caltech/T. Pyle (SSC)

Perechea catapulta


Un alt sistem binar cu comportament ciudat, numit AE Aquarii, este compus dintr-o stea normala si o pitica alba. Mult mai mica si mai densa, pitica alba pare ca absoarbe materie din companioana sa mai mare. In timp ce acest lucru, in mod normal, ar determina pitica alba sa acumuleze masa, i acest caz pare sa arunce cu putere materia in loc s-o acumuleze. Astronomii considera ca, datorita vitezei mari de rotatie si a unui camp electromagnetic foarte puternic, sunt elementele ce stau in spatele acestui comportament ciudat, determinand steau sa arunce un flux de materie care emite un spectru larg de radiatie, vizibila chiar daca este aflata la 330 ani-lumina, in celalalt capat al galaxiei.

Credit: Casey Reed

Tanara Pitica Alba

Stralucitoarea stea albastra care adomina aceasta fotografie nu este o pitica alba,dar punctul acela mult mai salb in intensitate din  partea stanga jos cu sigurana este. Cele doua stele sunt numite Sirius A si respectiv Sirius B si formeaza un sistem binar. Sirius B, este cea mai apropiata pitica alba de Pamant, la aproape 8.6 ani-lumina, ea prezinta o irezistibila oportunitate pentru crecetare, cat timp astronomii pot separa lumina ei de ce a companioanei sale mult mai stralucitoare. Sirius B este mai mica de cat Pamantul, dar avand o masa de multe ori mai mare, care-i confera un camp gravitational 350,000 de ori mai puternic de cat cel al planetei noastre. Daca o persoana de 70 kilograme ar sta pe Sirius B ar cantari 158 milioane Kg.

Imagine: NASA, ESA, H. Bond (STScI) and M. Barstow (University of Leicester)

Dansand in eternitate

Imagine: : NASA/Tod Strohmayer (GSFC)/Dana Berry (Observatorul in spectrul X-Ray Chandra)

In imagine vedem doua stele Pitice Albe in sistemul binar J0806, care se invart una un jurul celeilalte, intr-o spirala fara sfarsit. Cele doua Pitice Albe orbiteaza una in jurul celeilalte la fiecare 321 secunde, si astronomii considera ca viteza cu care orbiteaza este in crestere, insemnand ca sunt destinate sa se ciocneasca, contopindu-se intr-o masa mai mare. Sistemul acesta dens se afla la o distanta de 1600 ani lumina , astro fizicienii considera ca in urma impactului s-ar crea valuri de unde gravitationale, sau distorsiuni in cubura spatio-temporala, prezise de teoria relativitatii generalizate a lui Einstein.

 

credit: Clara Moskowitz

Cernobyl – Fukushima – cine mai urmeaza ?

Astazi 26 aprilie se implinesc 25 de ani de la dezastrul de la Cernobyl, si foarte putine zile de la cel de la Fukushima, si inca nu am intels de ce trebuie sa folosim o tehnologie atat de periculoasa, oare cati oameni trebuie sa mai moara, ca sa realizam, ca energia atomului are un pret foarte ridicat. Se plateste cu vieti, multe vieti umane, dar asta nu este tot, impactul asupra mediului, este de ne conceput. Dintre toate sursele de energie, de ce trebuie sa le alegem doar pe cele care sunt si cele mai periculoase? Trebuie sa gasim o noua sursa de energie, si asta foarte repede, – Daca ne gandim ce a putut sa faca un reactor la Cernobyl, – imagineaza-ti ce se poate intampla daca din anumite cauze, care nu tin de nimeni si de nimic de pe pamant, s-ar intrerupe alimentarea cu energie electrica a sistemelor de racire la reactoarele din intreaga lume, si crede-ma ca nu sunt putine. Stiu ca o sa spui: ce se poate intampla ?, Ce ar putea oare sa opreasca alimentarea cu energie a intregii planete?, si pe buna dreptate, dar daca, sa presupunem prin absurd ca se poate intampla, ce vom face ? Unde sa mai fugim atunci?
Avem o singura planeta, care este casa noastra, si fata de care avem o datorie sfanta, de a o conserva pentru generatiile viitoare, pentru  copii si nepotii nostri. Stii, cele mai bune lucruri sunt gratuite, asa ar trebuie sa ramana, asa ar trebui sa fie si cu energia, de ce trebuie sa existe un furnizor mare, de ce sa nu ne producem fiecare energia necesara, se poate, si este mai fiabil, mai ieftin, si fara sa aiba un impcat asupra mediului. NU am sa spun acum care sunt posibilitatile la care m-am gandit, o sa te las pe tine, cititorule, sa te gandesti ce ai faca daca de maine nu ar mai curge curent electric pe firele bine cunoscute. Te lasa sa te gandesti, pentru ca eu am deja nu una, ci mai multe solutii, dar pana atunci vreau sa ne gandim fiecare, le ceea ce facem si cum facem cu energia electrica, pentru ca pentru a o produce se folosesc tehnologii periculoase, si daunatoare vietii. Sper ca, copii nepotilor mei, sa mai poate sti cum arata cerul albastru, si iarba verde de acasa …