מערכת ייחודית זו תסיים את חייה בקריסה אלימה של בן הזוג לתוך החור השחור * בתגלית, שבוצעה באמצעות טלסקופ החלל צ'נדרה ושתפורסם היום (18.10.2007) בכתב העת נייצ'ר שותפים גם חוקרים ישראליים * ראיון עם פרופ' צבי מזא"ה
An international team of astronomers with the participation of Israeli astronomers managed to measure the mass of a black hole moving around its partner in the neighboring galaxy M33, which is about 3 million light-years away from Earth, and it turns out that it is a body with a huge mass 15.7 times that of our Sun. Until now, such a large mass has not been measured in a stellar black hole, and this discovery was made possible due to the proximity of the black hole to another huge star - which has a mass of 70 solar masses. The two bodies orbit each other at a distance equal to a tenth of the distance between the Earth and the Sun, that is, almost within touching distance, from a cosmic point of view.
הצוות הישראלי כולל את פרופסור צבי מזא"ה, מנהל מכון סאקלר לאסטרונומיה של אוניברסיטת תל אביב, ותלמיד המחקר אבי שפורר. דיווח על המחקר פורץ הדרך מופיע במהדורת ה-18 באוקטובר של הירחון המדעי היוקרתי נייצ'ר (Nature).
Black holes moving together with their partners have been known for about 40 years. According to the accepted theory, such a system began its life as a system of two stars moving around each other in space. The heavier star of the two ended its life in a massive explosion called a supernova, which is created by the collapse of the star into its center, and shines with a bright light billions of times stronger than the sun's light. At the end of the explosion, a black hole remains in the core of the exploding star, which continues to surround its partner. Material passing from the companion to the black hole falls at enormous speeds to the rim of the black hole, heats up to a temperature of millions of degrees, and before entering the black hole succeeds in emitting X-rays (X-rays) that were picked up by the Chandra spacecraft.
"אני נפעם מהעובדה שעולה בידינו לחקור חורים שחורים, שרק בגלל תורת היחסות הכללית של איינשטיין יכולנו לשער את קיומם" אומר פרופסור מזא"ה: "החלליות החדישות והטלסקופים הענקיים מאפשרים לנו לחקור מערכות בחלל הנראות כאילו נלקחו מסרט של מדע בדיוני. המציאות המתגלית לעינינו עולה על כל דמיון אנושי".
A black hole is formed as a result of the collapse of a star at the end of its life (when most of the hydrogen in it has already turned into helium). Although all stars collapse, if they are small, on the order of our Sun, they end their lives as white dwarfs after experiencing a period of inflation of their atmosphere as red giants. Stars whose mass at the time of collapse is greater - several solar masses, collapse under their own weight to such an extent that the atoms are no longer able to surround the nucleus and the neutrons in the nucleus come closer to each other, leaving a compact star - the size of the Earth and with a mass greater than that of the Sun. If the star is larger, from 10 solar masses or more (although the exact limit has not been measured) the self-gravity of the collapsing star is so great that even the neutrons collapse and it actually collapses into one point in space - a black hole. Such a black hole is simply called a stellar black hole. There is another type of black holes, more common at least in terms of the ability to detect them - black holes located in the centers of most galaxies. The mass of these black holes is millions of solar masses, and the hypothesis is that they were formed from the merger of stellar black holes that also swallowed stellar and interstellar matter that came their way.
Stellar black holes are very difficult to detect. So far no more than 10-15 of these have been discovered. If such a black hole were standing on the outskirts of the solar system, we would not feel it until some stray comet fell into it, and when it reached the threshold of the black hole it would emit radiation in the X-ray range. Therefore, most of the stellar black holes that have been discovered are those that are members of a binary star system, meaning that they orbit another star (or it orbits them) in such proximity that the solar wind from that star hits the black hole, and when swallowing this material, the black hole emits X-rays.
The circumstances of the discovery are somewhat reminiscent of the discovery of planets outside the solar system - it was discovered thanks to the fact that the star it orbits hides it once every three and a half days for a few hours.
מדידת המסה נעשתה בעזרת תצפיות שבוצעו ע"י טלסקופ החלל בתחום קרני ה-X, צ'נדרה (Chandra) השייך לסוכנות החלל האמריקאית, נאסא (NASA), וטלסקופ הענק ג'מיני (Gemini), הממוקם במרומי ההר הגבוה בהוואי. מדידה זו הופכת את M33 X-7 לחור השחור הכבד ביותר הידוע עד כה במערכת כפולה.
התיאוריות המקובלות של התפתחות כוכבים כבדים מתקשות להסביר את תכונות המערכת הכפולה M33 X-7. הכוכב שממנו נוצר החור השחור היה צריך להיות כבד יותר מבן זוגו כדי שיהפוך הראשון לחור שחור. רדיוסו של כוכב כבד כל כך גדול יותר מגודלה הנוכחי של המערכת הכפולה. מכאן, שהכוכבים המקוריים נוצרו ככל הנראה במרחק גדול יותר ממרחקם הנוכחי והתקרבו זה לזה כשהם נמצאים בתוך אטמוספרה חיצונית משותפת. תהליך זה גורם בדרך כלל לכך שכמות גדולה של חומר תיזרק מן המערכת. על כן איננו מבינים לחלוטין כיצד הצליח הכוכב שהתפוצץ ליצור חור שחור הכבד פי 15.7 ממסת השמש. "תגלית זו מעלה תהיות בנוגע לאופן בו חור שחור כזה יכול היה להיווצר" אומר ג'רום אורוס מאוניברסיטת סאן דייגו שבארה"ב, המחבר הראשון של המאמר.
"זהו כוכב ענק שיש לו בן זוג שהוא חור שחור ענק", אומר ג'פרי מקלינטוק, מחבר נוסף של המאמר, מהמרכז לאסטרופיזיקה של מכון הסמיסוניאן ואוניברסיטת הרווארד בקיימברידג', מסצ'וסצס. "בסופו של דבר גם בן הזוג הכוכבי יסיים את חייו בהתפוצצות סופרנובה ואז תיווצר מערכת כפולה ובה שני חורים שחורים."
וולפגנג פיצ' ממכון מקס פלנק שליד מינכן, גרמניה, מחבר נוסף של המאמר, היה המחבר הראשון של מאמר קודם שגילה את החור השחור ע"י שימוש בתצפיות שנערכו בטלסקופ החלל צ'נדרה. M33 X-7 הינו החור השחור הראשון שהתגלה במערכת כפולה בה מתרחשים ליקויים, שבהם בן הזוג מסתיר את החור השחור וסביבתו באופן מחזורי. ליקויים אלו מאפשרים למדוד את המסות של החור השחור ובן זוגו באופן מדויק ביותר. "משום שהחור השחור לוקה ומשום שיש לו מסה גדולה כל כך הוא מהווה הזדמנות ייחודית לבחינת תיאוריות אסטרופיזיקליות מקובלות" אומר פיץ'.
How was the discovery made?
פרופ' מזא"ה: "החללית הסתכלה על האיזור המכיל חלק מגלקסיה M-33 במשך 26 שעות רצופות. המדענים בכדור הארץ קיבלו את נתוני התצפיות וחילקו ביניהם את הכוכבים הבודדים כדי לנתחם. הניתוח הראה שעוצמת קרינת ה-ס של המקור הזה, המקור הזה –X-7 עוצמת קרינת ה-X שלו יורדת כמעט לאפס, מחכים כמה שעות ופתאום זה עולה חזרה. כלומר יש פה ליקוי. כשרואים דבר כזה והוא חוזר על עצמו אתה מבין שיש פה איזושהי תופעה מחזורית – שני כוכבים שמסתובבים אחד סביב השני ומקור קרינת הX מוסתר על ידי בן הזוג. כך גילינו שיש פה ליקוי – מערכת כפולה המסתובבת סביב עצמה וזה הדבר הייחודי ביותר במערכת הייחודית – שמקור קרינת ה-X עובר ליקוי כל שלושה וחצי ימים, נעלם לכמה שעות וחוזר לאחר מכן להקרין X במלוא עוצמתו.
How do you know it's actually a black hole?
Mainly according to the mass. We made very detailed observations with optical telescopes to follow the partner and from the cycle time and the measurement of the speed the partner moved and the eclipse, we can estimate the mass of the X-ray source and it comes out to be 15.7 solar masses, and it cannot be any other compact star that we know, not a white dwarf, Not a neutron star, all of these things have a mass of 3/XNUMX and XNUMX solar masses. The nature of the X-rays also shows us that such X-rays are usually emitted very close to the rim of the black hole.
Does he threaten to swallow his partner?
They go around each other very close but safe. At the current rate to consume all the mass will take hundreds of millions of years. Long before the companion will swell and spill dramatically into the black hole, the system will be much louder than today.
In the illustration taken from the article appearing this week in the prestigious journal Nature, the stages of development of the double star are described. Star number 1 begins to swell (phase a) until its envelope engulfs star number 2 (phase b). During the movement of star 2, the envelope of star 1 is thrown away and the two stars approach (step c).
Then star 1 explodes, creating the newly discovered black hole.
Comments
Dedicated to Judah from the Archangel, the "Eternal Treasurer" for the worlds.
When his heart will stop and he will be silent
At the time of death, you will always be an orphan
When it goes out, let the candle light up
There won't be, there wasn't, like nothing.
When he joined the low in Natz
When the constant angel will sign
When he allowed Ora to seal
No animal will live without protection.
When he betrayed the justice to strive
When the words of the innocent will be devoured
When his spirit leaves the outside
He will not see, he did not see, and he has no right.
To my father
Below is a quote from the article
"This source - X-7, its X-ray intensity drops to almost zero, wait a few hours and suddenly it rises again. That means there is an eclipse here"
I mean it was completely covered for a few hours which is a bit inconsistent with your proposal, but maybe.
I think it's worth trying to ask Professor Zvi Maza to clarify the issue.
Sabdarmish Yehuda
Come on, it's just business.
A simple explanation for the question unfolding here!
For there to be a total eclipse, the Earth has to be in the plane of rotation of the two stars. If the Earth (or because of the great distance, the entire solar system) will be a little on the side of the plane. The eclipse will be partial, so the intensity of the radiation will decrease, but not to zero!!
You have noticed, defamatory people always hide behind cover names. I will not respond to such and suggest others do so as well.
Sabdarmish Yehuda
You are a bunch of people who live in the world of imagination, little children who come up with ideas that they cannot understand, without any argument or lack of proof.
To Ami Bakr Shalom
Idush will be carried out if a heavy object stands between us and the special star - whose radiation will be special, meaning that the one who will do the Idush here will be the second star whose mass is about 70 solar masses. It's true that it's a heavy mass and I suppose it could do some serious cleaning. If I know that our sun rotates about 1.6 seconds of arc, then a star seventy times heavier will rotate for about a few tens of seconds of arc and maybe even a minute of arc, but this is not enough because here the remaining proximity of the black hole to the other star comes into account, which is about 15 million km M, one tenth of an astronomical unit. This is too close and you need a magnification much larger than a minute of arc to get the result you are talking about. That is, I don't think that magnification can explain the weak X-radiation during the eclipse.
There are bits and pieces of information about the discovery here and it is difficult for me to analyze beyond what is written in the article, also because of my lack of knowledge on the subject of radiation from stars in general, and black holes in particular.
And as for the lecture, believe me that Givat Olga near Hadera is half an hour's drive away and the observatory there is simply amazing, so maybe it's still worth making the effort.
I would be happy if someone would lift the glove and invite me to lecture in the Tel Aviv area.
Maybe you are Mr. Ami Bachar, you have connections, I would be happy to lecture.
All the best
Sabdarmish Yehuda
Lesbadramish Yehuda,
My question may be stupid, but is there a possibility that the black hole's gravitational pull is the one that causes the radiation from the star, during the eclipse, to reach our sensors and therefore the radiation does not really reach zero? Between the telescope and the big star there is, let's say, a black hole whose measured radiation is literally zero, but from its sides several energy jets originating from the star manage to interfere and reach the measuring device.
And for another matter - when will you give a lecture in less dark places? For example in Tel Aviv?
Liron
We agree with the X-ray figure, but note the quote from the article:-
"Also the nature of the X-ray shows us that such X-ray is usually emitted very close to the rim of the black hole"
The words usually leave some doubt.
In addition, it will be written in the article that the X-radiation drops to almost = zero during the eclipse, and I ask why not to zero (not almost), is it due to the fact that such radiation also has other sources?, so how confident are we that it is a black hole?
And regarding the dark mass, well, here we agree between us and if you would like to strengthen your views on the dark mass, you are invited to my lecture on this subject this coming Sunday, October 21.10.2007, XNUMX at eight o'clock in the evening at Technode in Givat Olga.
There I will analyze all possible alternatives for explaining the movement of spiral galaxies, except for the dark mass.
Of course, the rest of Israel is also invited.
Have a good day
Sabdarmish Yehuda
To Ami - there is a simple answer to this, there was an embargo until eight in the evening but I was at the event all day and I didn't have time to work on the article. At YNET I wrote a version for the general public and sent it, and I added all the scientific stuff towards the end of the article. I needed time and concentration for this, and also time to take care of the photos and upload them to the website. And I didn't want to do it on one leg.
A black hole is not so unconventional. It has been studied
Using general relativity and quanta (strings).
We argued that today it is less clear to science what that uniqueness is
But in the future it will probably become clear. Pretty clear black black exists.
It is quite clear from the characteristics described that it is not something else.
It emits X-rays.
Much less conventional is the dark matter that clouds like
A black cloud over physics. In my opinion, the two answers are related - but since this is not a first-line scientific theory, I will not explain why.
What will a person who does not believe in the reality of black holes do when he reads an article like this.
First of all, I was convinced of the following details:-
There are two stars orbiting each other around a common center of gravity, one 15.7 solar masses and the other 79 solar masses. The smaller star emits X-rays.
I have no argument with the authors of the article about this.
But I wasn't convinced it had to be a black hole.
Is there really no other, conventional explanation for the above phenomenon?
Sabdarmish Yehuda
At the end of the process, one big black hole with approximately 85.7 solar masses will be obtained? And what will be his movement after the union? Will it be ejected from the force of its rotation around the shrinking large star as the black hole's mass increases?
Will over time the heavy star, whose common center of mass is probably closer to it, start to thin out while the black hole gets fatter and the common center of mass will start to move towards the black hole until at some point the whole star will be concentrated in the singularity? In between while all this is happening will instead of the black hole rotating around the star, the star will start rotating around the growing black hole.
Standard black guy, is the percentage of matter similar to the percentage of matter in the universe? Can a black hole be created from dark matter in advance and if so what is the difference in the radiation on the event horizon of such a black hole - if there is any difference at all?
And the most important question: Avi Bilizovsky - why publish an article by the scientist first on YNET before it is published in the scientist? Is unit pride also dark pride?
Greetings friends and thanks for a great article
Ami Bachar