Last daily update:
2019-08-19 17:10:17 UTC
Last incremental update:
2019-08-19 22:33:44 UTC
2019-08-19 22:40:11 UTC
After last server update I have also prepared NFS based folders with results databases.
So, here is rsults page where you can download all processed data from our project.
For next few days I will not generate more tasks as I'm preparing to server software update.
The software will require few restarts and is planned later in this week - I will inform you when it happens exactly.
After a series of papers on gravitational wave sources, we published results concerning ultra-luminous X-ray sources. In the paper we analyse the anisotropic emission of radiation from these sources and show that the actual population of ultra-luminous X-ray sources differs from the observed one. Particularly, in flux limited surveys, the observed population will be highly biased toward black hole accretors, whereas neutron star accretors dominate volume-limited observations.
The work can be found here https://arxiv.org/abs/1811.08998
Sorry for late notification!
Another research on the famous GW170817 source, which used data obtained from the Universe@Home project, have been published last year. In this study, it was shown that the merger rates of double neutron stars (calculated from one direct observation) stay in contradiction with these inferred from the observations of double pulsars in our Galaxy. The reason behind this tension is the delay time distribution which favours short delays. The study highlights the problem that scientist encounter trying to connect evolutionary predictions and the observations of the first double neutron star merger.
The original paper can be found here:
My apologies for letting you know so late! In the previous year a very important paper appeared which partially used results from the Universe@Home project.
An international cooperation led by prof. Belczynski investigated the importance of different evolutionary scenarios leading to a double neutron star merger. The work was motivated by the ground-breaking discovery of GW170817 made by LIGO/Virgo collaboration (see e.g. https://www.ligo.caltech.edu/page/press-release-gw170817). The scenarios included the isolated binary evolution which was exclusively calculated on U@H. The simulations showed that among currently considered formation scenarios this one is the most promising. Such a result may lead to a larger interest put in isolated binary evolution simulations and, consequently, to the results obtained thanks to the cooperation of thousands of U@H volunteers.
The original work can be found for example here: https://arxiv.org/abs/1712.00632
As Krzysztof have already said, we got a grant in the Maestro program. It will allow to continue the project for the next few years. We hope that the project will still provide an exceptionally computational power for the science.
The Maestro program of the National Science Centre aims at providing funding for pioneering research. The research should be done by groups led by senior scientists. The projects must result in extending our understanding of physical phenomena and potentially lead to scientific discoveries. It is one of the biggest funding programs of the NSC.
You can read about the scientific goals here
for Polish see
It looks like we got some funding for our project :)
More info tomorrow (or in next few days) :)
Recently we had some problems with validation process. Now the problems are sorted and all WU's from new batch are pointed correctly.
Also, new applications version are available for:
At the moment there is no app for Android but I hope it will be available soon.
I just get message form server room staff:
A big shutdown of our network is coming!
Due to the measurements of the power grid, we have to switch off
the computer network in the whole building from 11 to 13 January 2019.
During this time, no computers will be working and even there will be
no voltage in the electrical sockets.
We are very sorry for the inconvenience, but we have little influence on it.
As you know, I'm working on Universe@Home for some years now. I was also one of creators and admins of Radioactive@Home project and few another BOINC projects.
Unfortunately, for long time I'm working on this project voluntarily as is no funds on it to my role.
Because of this, I will ask you for support on my Patreon profile.
As you probably notice we had serious crash on server.
Unfortunately, both SSD's with project database in RAID1 configuration died simultaneously...
I have restored database from backup on second server but data are 24h oldest then crash time.
Tomorrow (24th October 2018) I will attempt to update BOINC server software.
This will cause number of server stops and possible some our web site problems.
Between 13-18 April the server room in Astronomical Center will be renovated. Therefore, our servers will probably be shut down.
Sorry for the inconvenience!
On our server just start new BHDB (Black Hole Database) application.
First work units release will be testing one, to check if everything is ok with application and points system :)
In near future we will publish more information about it.
As you know, security issues arrive to computers world (Meltdown and Spectre)...
Yes, we work on it, but the problem is that is still no patch for this bugs, so we decide to slow down until "big boys" find solution...
Simulations done with the use of Universe@Home and the analysis performed in the cooperation between University of Warsaw (Poland) and University of Ferrara (Italy) resulted in a research paper publication in the Astrophycial Journal, one of the highest ranked scientific journals worldwide! The article can be found on arXiv: https://arxiv.org/abs/1707.01586
The research on hypothetical quark stars was the first of its kind and gave a few very interesting conclusions. Although we showed that the presence of these objects cannot be proved or rejected on the base of available observations, quark stars have a potential to explain the long gamma ray burst phenomena and the so called "strangelets pollution" problem.
Symulacje wykonane z wykorzystaniem Universe@Home i analiza wynik
Tomorrow (28th October 2017) our servers will be switched off due to electricity maintenance works in servers room.
AAS Nova, a service run by American Astronomical Society, featured our research on ultraluminous X-ray sources! Authors of the note emphasize the fact that data was acquired through volunteer computing. You can see the note on
AAS Nova, serwis prowadzony przez Ameryka?skie Towarzystwo Astronomiczne, wyr
As some users are reporting serious problems with finished WU's uploading I have to dry server, unload queue to get more info what's happaend.
So, we will not generate new taks at least for next two-three weeks.
Some results of all of us work are available now under "Server->Our results" menu.
There are also files with processed data available for all interested in this subject.
In next few days I will add also files for QuarkStars application entry.
For a few month we were analyzing a vast amount of data we acquired thanks to the project and finally we published our results. You can find the article here (https://arxiv.org/abs/1705.06155).
Thanks to a large amount of data, we were able to show that ULXs might indeed be a very short phase of extreme accretion in XRBs and not any exotic objects. Our side-result showed that a non-monotonic relation exist between the number of ULXs in a galaxy and the average metallicity (i.e. fraction of heavy ions in stars), which may be useful for obtaining additional information about stellar populations.
We plan to make further research in this field!
We are planning maintenance break on 28th and 29th of August.
In this two days we will move main server and work station to new location and also we will connect another new server.
The new server will be used as storage machine to serve our results database on Internet and make it available for every interested person or institution.
Because I have to go abroad for few days it will be short delay in WU's deployment.
I will create some more about Wednesday.
In next few days I will release only short series of WU in different applications because I have to test new work generators for it.
Also, I will start to prepare database with all results for that WU's and slowly start to prepare web interface to download it for everybody who will be interested. This can take one to two weeks as I have other tasks to do in other projects as well :)
Most of you have probably noticed that we?ve started to introduce a new code to
Universe@Home. The changes are content-related (new models of astrophysical
phenomena) as well as technical (errors in the code). We hope that they will
solve the problems some of you encountered in the previous version of the code.
We?re still going to do research oriented towards binary stars and their
influence on their surroundings. New results, which will be published shortly,
have indicated new directions. Thanks to your help, our work will be continued!
Due to moving server to another building tomorrow (31th March) we need to shutdown our main server for few hours.
This will start about 10am UTC and it will take about 4 hours.
The investigation of ULX's nature is still in progress and currently we are
waiting for feedback from our collaborators. Meanwhile, I want to share with you
a figure of the evolution of a typical ULX with black hole accretor.
To make the long story short, two massive stars bore in a binary. One which is
heavier expands as a result of its nuclear evolution and starts to shed mass
onto its companion.This mass transfer is dynamically unstable and the second
star becomes engulfed with the primary star's matter. We call this phase a
common envelope and it happens typically when the system's age is between 4 and
5 million years.
If the companion has enough orbital energy, the common envelope is rejected and
the stars' separation shrinks significantly. The primary needs now less than
100,000 years to collapse and form a black hole.
The system's orbital energy is constantly emitted in gravitational waves, which
results in further separation shrinkage. Simultaneously, the secondary star
expands. If it manages to commence the mass transfer onto the black hole within
the first 500 million years (typically during the first 10-20 million years),
the flow will be strong enough to power a ULX.
Nadal trwa badanie w?a?ciwo?ci ULX, a obecnie czekamy na informacje zwrotn? od
After vacation time, we are getting back to work! There are some significant
goals in front of the U@H and we still count on your help!
First of all, we are continuing our cooperation with Cambridge and Ferrara.
Scientist are becoming more and more aware of the project and appreciate the
help in obtaining necessary data. The manuscript about ULXs should be published
in the nearest future. We think the conclusions will bring about a vivid
discussion. We are also preparing large-scale simulations for the BHspin
application which will provide valuable predictions of gravitational waves for
the next LIGO runs.
From the technical point of view, we are going to make several improvements this
year. An additional server for processing data will be installed. Additionally,
applications will be adapted for the GPU computing. We also plan to establish a
database with public access which will store the results and possibly provide
some visualisation tools.
As always, we will keep you informed on the progress and your feedback will
still be highly appreciated!
Po wakacjach wracamy do pracy! Przed U@H wiele wyzwa? i nadal liczymy na Wasz?
pomoc! Przede wszystkim nadal kontynuujemy wspó?prac? z Cambridge i Ferrar?.
Naukowcy coraz cz??ciej s?ysz? o projekcie i doceniaj? pomoc w pozyskiwaniu
danych. Praca dotycz?ca ULXów zostanie wkrótce opublikowana. S?dzimy, ?e wnioski
wywo?aj? ?yw? dyskusj?. Przygotowujemy równie? wielkoskalowe symulacje na
aplikacj? BHspin. Dostarczy ona wa?nych prognoz na temat fal grawitacyjnych
dla kolejnych obserwacji LIGO.
Od strony technicznej, dokonamy w tym roku kilku ulepsze?. Zainstalujemy
dodatkowy serwer do przetwarzania danych. Ponadto dostosujemy aplikacje do
oblicze? na GPU. Planujemy równie? stworzy? baz? danych z dost?pem publicznym,
która b?dzie s?u?y?a przechowywaniu wyników i by? mo?e dostarczy równie?
narz?dzi do ich wizualizacji.
Jak zawsze b?dziemy Was informowa? o post?pach i bardzo ceni? Wasze uwagi!
Today we had ordered two SSD drives for our server. The drives will be used for database use which should significantly improve server performance.
I will setup it on Friday or Saturday depend of delivery day and during the process server will be switched off.
Ze wzgl?du na ograniczenia silnika forum, zdecydowa?em si? na opublikowanie posta o teoretycznym aspekcie pracy nad nasz? aplikacj? GPU na blogu DobreProgramy
I have published some theoretical informations about GPU aspects of our application on DobreProgramy portal (in Polish).
Regarding to latest problems with tasks submissions to your computers we plan to make some maintenance work on our server and results analyse machine at the end of this week or start of next one.
The server will be stopped for about 6 hours but I will publish info when this happens before we start.
The results of the Universe@Home project will be used by the University of
Cambridge! The cooperation will concern the reionisation of the Universe
throughout the cosmic time. This process has a huge impact on the evolution of
stars and galaxies.
Although University of Cambridge has a vast computational power, the number of
project run on their computers and other problems made Universe@Home a
We will let you know about the details of the project as soon as we obtain the
Wyniki otrzymywane w ramach projektu Universe@Home b?d? wykorzystane na
Uniwersytecie w Cambridge! Wspó?praca b?dzie dotyczy? rejonizacji (ponownej
jonizacji) we Wszech?wiata. Proces ten ma postawowe znaczenie dla
ewolucji gwiazd i galaktyk.
Pomimo tego, ?e Uniwersytet w Cambridge ma pot?rzne komputery, ilo?? projektów
które s? tam prowadzene i inne problemy sprawiaj?, ?e Universe@Home stanowi
bardzo obiecuj?c? alternatyw?.
O szczegó?ach damy zna? jak tylko otrzymamy pierwsze rezultaty tego projektu.
We have just started the tests of a new application. The main goal is to analyse
the possibility of observational detection of quark stars. These objects are
composed of quarks, i.e. particles smaller than neutron or proton. Quark stars are
nearly similar to neutron stars, but we may observe their impact on stellar
W?a?nie uruchomili?my now? aplikacj?. Jej g?ównym celem jest analiza mo?liwo?ci
obserwacyjnej detekcji gwiazd kwarkowych. Te obiekty sk?adaj? si? z kwarków,
czyli cz?stek mniejszych ni? neutrony czy protony. Gwiazdy kwarkowe s? prawie
identyczne z gwiazdami neutronowymi, ale jest mo?liwe wyznaczenie ich wp?ywu na
Results from the Universe@Home project were published in the most prominent
scientific journal, Nature! The article depicts a stellar evolutionary scenario
that leads to the formation of double black holes, which are probable
sources of gravitational waves similar to those observed recently.
It is a sequel to the article from year 2010, which predicted that the first
detection of gravitational waves will rather origin from a double black hole
merger than from a
double neutron star merger. The latter had been favoured by the majority of
scientists until recent discoveries.
The links to the article are provided below. Please notice especially the
acknowledgements in the Nature publication.
http://arxiv.org/pdf/1602.04531v2 (this article is identical to the Nature
publication, which does not have a free access:
The 2010 paper:
Wyniki otrzymane w ramach projektu Universe@Home zosta?y opublikowane w
najbardziej presti?owym czasopi?mie naukowym Nature! Artyku? opisuje evolucj?
gwiazdow?, która prowadzi do formowania si? podwójnych czarnych dziur. S? one
potencjalnymi ?ród?ami fal grawitacyjnych, takich jakie te, które zaobserwowano
Jest to uaktualniona wersja artyku?u z 2010 roku, w którym przewidziano, ?e
pierwsza detekcja fal grawitacyjny b?dzie pochodzi?a z koalescencji czarnych
dziur, a nie dwóch gwiazd neutronowych. Ta druga opcja by?a przewidywana przez
wi?kszo?? naukowców, co zmieni?y dopiero niedawne odkrycia.
Poni?ej znajdziecie namiary na oba artyku?y. Zwróccie szczególnie uwag? na
podzi?kowania w Nature.
http://arxiv.org/pdf/1602.04531v2 (tan artyku? jest identyczny z tym w Nature,
który nie jest niestety dost?pny za darmo:
The 2010 paper:
Better late than never, so a few words about how Pentathlon looks from the
administrator?s point of view
As I have explained before, loads of pressure hits the server with thousands of
computers connecting with "bunkered" WU's. Usually we had ~45'000-50'000 tasks
in progress and just before the start the quantity grew up to 250'000 and later
stayed at the level of about 220'000-240'000 tasks in progress.
As you probably noticed from the picture showed in the other topic the only
problem we had was with hard disk speed because of thousands database operations
in the background of other server tasks.
As you can see in the picture below, almost in the whole Pentathlon competition
time disk utilisation was at 100% or just below it. We usually have stable disk
utilisation at 40-50%.
In the middle of the competition I also switched off all unnecessary daemons and
other software which usually works on our server and even without them the
server was off-line for 30 minutes.
Now, the situation is stable. We still have more tasks in progress than before
the competition (which makes us very happy) and we will also prepare to buy some
SSD's asap :)
Thank you very much for your power in Pentathlon and obviously for every day
with us and our tasks :)
Lepiej pó?no ni? wcale. Tak wi?c kilka s?ów o tym jak Pentathlon wygl?da? z
punktu widzenia administratora
Jak t?umaczy?em wcze?niej, bardzo du?e obci??enie pojawia si? na serwerze gdy
tysi?ce komputerów pod??cz? si? ze swoimi "zbunkrowanymi" WU. Zwykle mamy
~45'000-50'000 zada? w toku, a zaraz przed rozpocz?ciem ta ilo?? wzros?a do
250'000, a pó?niej pozosta?a na poziomie 220'000-240'000 zada? w toku.
Jak pewnie zauwa?yli?cie na za??czonym obrazku, jedyny problem, jaki mieli?my to
opó?nienia w operacjach dyskowych i wynika? on z tysi?cy operacji na bazie danych.
Równie? wida? na poni?szym obrazku, ?e prawie przez ca?y czas trwania konkursu
Pentathlon wykorzystanie dysku by?o na poziomie 100% lub nieco poni?ej. Zwykle
mamy wykorzystanie dysku na stabilnym poziomie 40-50%.
W ?rodku konkursu wy??czy?em wszystkie zb?dne demony i oprogramowanie zwykle
pracuj?ce/dzia?aj?ce na serwerze i nawet bez nich serwer by? niedost?pny przez
Teraz sytuacja jest stabilna. Nadal mamy wi?cej zada? w toku ni? przed
konkursem (co bardzo nas cieszy) i b?dziemy si? przygotowywa? do kupienia dysków
SSD tak szybko jak to mo?liwe.
Dzi?kujemy bardzo za zaanga?owanie w Pentathlon i oczywi?cie za ka?dy dzie? z
nami i z naszymi zadaniami :)
As most of you probably knows, we are a part of BOINC Pentathlon competition.
Our server will be tested by you from 2016-06-12 00:00:00 UTC until 2016-06-19 00:00:00 UTC .
I have a pleasure to inform you, unless you already know, that prof. Krzysztof Belczy?ski,
the PI of Universe@Home project, in recognition for his involvement in discovery of gravitational
waves, was awarded recently with the Medal of Nicolas Copernicus and the Breakthrough Prize.
The former is the most prestigious prize awarded by the Polish Academy of Sciences. The latter is an
international award bestowed for remarkable scientific outcome. It was awarded for the whole group,
which took part in the research.
The results from the Universe@Home project are still used to increase our understanding of
gravitational waves and their role in the Universe.
Mam przyjemno?? poinformowa? Was, cho? mo?liwe, ?e ju? wiecie, ?e prof. Krzysztof Belczy?ski,
kierownik projektu Universe@Home, w uznaniu swoich zas?ug w odkryciu fal grawitacyjnych, zosta?
nagrodzony Medalem im. Miko?aja Kopernika i Breakthrough Prize.
Pierwsza nagroda jest najbardziej presti?? przyznawan? przez Polsk? Akademi? Nauk. Druga
natomiast to mi?dzynarodowa nagroda przyznawana za znacz?ce odkrycia naukowe. Zosta?a ona
przyznana ca?ej grupie bior?cej udzia? w badaniach.
Wyniki otrzymywane w ramach projektu Universe@Home s? ci?gle u?ywane do poszerzania naszej
wiedzy na temat fal grawitacyjnych i ich roli we Wszech?wiecie.
Wersja polskoj?zyczna poni?ej
You have already heard about the discovery of gravitational waves from a merger
of double black hole. In our project, specifically in the BHspin application, we
were also working on the evolution of such systems. If you are interested in the
way how they form and evolve, we prepared for you the description of the evolution of
a typical system, which results in the emission of gravitational waves like these
from the recent observations. You may found the text, together with a nice plot,
in the forum's science section. Please enjoy!
Prawdopodobnie wiecie ju? o odkryciu fal grawitacyjnych z koalescencji czarnych
dziur. W naszym projekcie, a konkretnie za po?rednictwem aplikacji BHspin,
analizowali?my ewolucj? takich systemów. Je?eli jeste?cie zainteresowani tym jak
podwójne czarne dziury si? tworz?, to przygotowali?my dla was opis
popularnonaukowy jednego z typowych systemów. Jego ewolucja prowadzi do emisji
fali grawitacyjnej jak ta z niedawnych obserwacji. Tekst razem z pogl?dowym
rysunkiem mo?na znale?? na forum w dziale Science. Zapraszamy!
Few days ago we had added option to add yours real full name in preferences.
Setting it also allow us to publish it in future science publication as research supporters.
You have probably heard about the outstanding discovery of gravitational waves announced a week ago (e.g., http://www.nature.com/news/einstein-s-gravitational-waves-found-at-last-1.19361). It is a milestone in our understanding of the Nature. Universe@Home was not involved directly in the detection, but it is relevant to highlight, that already in year 2010, prof. Belczy?ski predicted, that the first gravitational waves observation will involve a double black hole merger, whereas most of the scientists claimed that it will concern a merger of neutron stars. The original paper can be found here: http://adsabs.harvard.edu/abs/2010ApJ...715L.138B.
Please observe that prof. Belczy?ski used then the same StarTrack code that we are using in the Universe@Home project! Of course, now we have a bit updated version. Therefore, the recent discovery proved the reliability of our methods!
If you like to learn more about gravitational waves, I recommend a thorough but comprehensible introduction by the discoverers http://www.ligo.org/science.php.
We have finished a bunch of models, which will be published shortly. However, still a lot more are waiting for investigation. In the case of ULXs we are working on the influence of more primordial matter composition on formation of these mysterious objects. The BHSPIN application concentrate on black holes spin (i.e., rotation), which influences the mass accretion processes (necessary for the detection of this latent objects), and emission of gravitational waves (a.k.a. propagation of space-time wrinkles). The last process is recently raises a unprecedented interest due to the rumours of its first observations. Predicted 100 years (precisely) gravitational waves have not been detected yet. Our results may play a significant role in understanding the observational results.
In polish public television appeared in the end of previous year a program about scientific computing considering also our project. Unfortunately it is available only in polish. You may found it here https://www.youtube.com/watch?v=iZIkjBXrcMM
I had compiled Mac OS version of ULX application.
Apologise if application will crash on your system (please report this to me) as I have no experience in Mac OS compiling.
If the application provide right results I will also add support for BHspin app.
Last week we prepared the ULX application which is closely related to the previous (now obsolete) X-ray application. It is investigating the possibility of connecting the Ultraluminous X-ray sources (ULX) with X-ray binaries (XRB). We want to make a comprehensive study far wider than the one from the test project which was published in September.
ULXs are one of the greatest conundrums currently investigated in astronomy and every month new observations are coming up. Our code is the best to deal with the problem of their nature from the theoretical side. ULXs are very rare systems. In our simulations only 1 XRB per 100 have a very short phase of such a high emission and only in some particular models.
If you have any questions of comments concerning this application, please put them in this thread.
As you might have noticed we added a new application recently. It is devoted to investigate the spin evolution of black holes.
When a black hole accretes matter, at the same time it accretes the angular momentum, which results in faster spinning. In this model we examine the influence of this process. What makes it particularly interesting is the fact the the LIGO observatory of gravitational waves started to operate recently. Therefore, in the near future, our theoretical predictions will be checked against observation.
Wojciech G?adysz, who cooperates with us in this project prepared a longer description of this problem which I posted in the Science section. I invite you to take a look.
I hope that you will become interested in this research!
Thanks to the user matszpk we can start Today testing Android version of our application.
Application will be available soon but only for users who mark "Test application" in their options.
We have made significant upgrades to the code, removed a few bugs, and incorporated new additional physics to widen our field of research.
Due to this fact we delete the remaining work units. These which are currently processed by users will stay unharmed and the points will be added as before. Tomorrow we will compile the new code and prepare new workunits.
If you find any problems with the new code, please let us know.
From new batch we start to send about 4 times longer work units...
Longer WU's allow us to check some models more deeply and also this change will unload server by giving us same data in less files...
We have just finished the primary tests of the new version of the code. This gave us a green light to start the computation of a grid of models. We want especially to test the brand new approach to the mass transfer between stars in binary systems and the physics of accretion onto compact objects (i.e., neutron stars and black holes). These processes have a fundamental role during the evolution of binaries. Moreover, they also influence the evolution of whole galaxies and even the Universe itself.
As soon as partial results will be obtained and analysed, we will provide you with more details and news.
Thanks for you help!
Yestarday I got new application for our project.
Currently I need to make some changes in work generator to make it compatible with new app.
I would like to make some WU's for new application in test mode and if everything will work fine - I will generate more WU's in next 2-3 days.
We made a poster to present the results of Universe@home project on the international conference. I must admit that the project itself gathered more interest among scientists than our results! Below you can find the poster. Generally it is the summary of the article but with more graphics.
Go here http://universeathome.pl/universe/img/poster.pdf for bigger version.
Till the end of the week I will provide for you descriptions of these typical evolutionary routes. This is exactly what your computers are calculating.
Please fill free to ask any other poster related questions in this thread.
For personal circumstances I am forced to go abroad for two weeks.
I'm not sure if I get any Internet connection over there and if not, during this period new tasks will not be generated.
Apologise for this...
Because I'm going abroad for a week tonight I will generate large quantity of work units on server late evening/overnight. Until all tasks on work generator finishes server will be stopped/delayed on some operations...
First series (12 - 'universe_xray_12_20000_1-100000_695' ) have bug in parameters file and can't finish - I have cancelled it on server, unfortunately some of you get it.
New one (13, 14) should be ok.
As I promised in previous message I provide you with a short explanation of the work we have done on the University of Warsaw using the data acquired with Universe@home project. I remind you that the article can be found at http://arxiv.org/pdf/1503.08745v1. The main subject of this article are the extreme ultra-luminous X-ray sources (EULX). Probably a bit enigmatic name, so I will start with explaining what they are.
Most stars in the Universe are the binary stars (i.e., two stars bound gravitationally). In such systems a lot of interesting phenomena occur that are prohibited for single stars.
Let's take a rare group of binary stars in which one object is the black hole (BH) and the companion is on such a close orbit that the mass is stripped from it by strong gravitational force. This material falls onto the BH but on the way it forms an accretion disk. Friction produces large temperatures which results in energetic radiation in X-ray band. We name such systems the X-ray binaries (XRB).
If we make the additional assumption that the X-ray emission is extremely energetic we will acquire the EULX systems. We are not sure what is the real nature of them. The BH may be very massive or may be similar in this case to its cousins in XRBs. Even the neutron stars (NS) are possible as accreting objects. These (and other) questions make EULX a perfect field for study.
In the presented paper we perform the numerical simulation to study the evolution of a large number of systems. In total we evolved a billion stars and from this awesome sample we dig out the rare systems whose X-ray emission is comparable to EULX. Then we performed the statistical studies and distinguished the evolutionary routes leading to the phases of this super-emission. We found that both BH and NS accretors are possible and that they should be easily differentiated by their companions.
The main outcome of this work is that EULXs are not separate group of objects among XRBs but they are a very common phase in the evolution of a large number of systems. This phase is very short (1-10,000 yr - extremely short in cosmic scale) but occurs so frequently that we are able to observe a few EULX at any time in the life of the Galaxy. Currently we observe about 500 ultra-luminous X-ray source (ULX) but only one EULX (10-1000 more luminous than ULX). The forthcoming article will deal with the regular ULXs.
As one of the our crunchers suggest, with new science discoveries we had to change our badges descriptions (visible when you move mouse cursor over it)...
I have a pleasure to announce that the first article of the Universe@home project is finished! It appeared today on the http://arXiv.org, which is the official place for posting scientific articles. The writing can be found here: http://arxiv.org/pdf/1503.08745.
On behalf of the team I would like to thank all the volunteers who participated in the Universe@home test project. We hope that this is only the beginning and you will still help us in comprehending the Universe.
Shortly, I will provide you with a summary of the work written in the less formal language but meanwhile I encourage you to take a look. Our project is mentioned there a few times. Especially, please note the acknowledgements.
I had to cancel whole '9' series of work units on server.
Please cancel all WU's with '9' as first number in WU name.
Apologise for inconvenience
It's important to mention to all crunchers that currently in our project all WU's generate large results files. For every single work unit results can take up to 70MB of compressed data (~400MB before compression) and this quantity of data must be uploaded back to server.
For crunchers with slow internet connection there is a risk that they possible get a problem with uploading files before deadline.
This will change in future but for current project demands the files with all data are required.
I would like to announce, that our main Universe@Home project server is officially started.
I believe, that our application is stable, checkpoints work correctly but as this server is just started, few things must be still corrected.