Grupowanie i uśrednianie obrazów Sagittarius A* i M87*
Dwie supermasywne czarne dziury, które obserwowano przy pomocy EHT, mają znaczące różnice w masie. M87* jest ponad tysiąc razy większ niż czarna dziura w centrum naszej galaktyki, Sgr A*. Oznacza, to że wokół Sgr A* gaz porusza się znacznie szybciej (skale czasowe w minutach) niż w przypadku M87* (skale czasowe od dni do tygodni). Gdyby użyć Dolomitów jako analogii, obserwowanie pasma górskiego odpowiadałoby całemu dniowi dla Sgr A*, ale zaledwie kilku minutom dla M87*, zachowując ten sam czas obserwacji na Ziemi.
Animacja zaczyna się pokazując precyzyjnie różne skale czasowe, ilustrując proces grupowania obrazu i uśredniania, używany do zobrazowania Sgr A* (po lewej) i M87* (po prawej). Wideo tłumaczy dlaczego w obserwacjach o długich ekspozycjach zmieniającego się obiektu możemy zrekonstruować różne możliwe obrazy tego samego pasma górskiego. Różne wyprodukowane obrazy są sortowane do czterech kategorii - zwanych grupami - zgodnie z głównymi cechami. Każdej grupie towarzyszy pionowy pasek wskazujący, jak często obraz tej grupy jest rekonstruowany z całej serii obrazów. Obrazy w każdej z grup są następnie uśredniane w dolnych panelach i rekonstruowany jest ostateczny średni obraz w górnej części, jako średnia ważona poszczególnych średnich dla grup (grupa z wyższym pionowym paskiem ma większą wagę w finalnym średnim obrazie).
Druga część wideo pokazuje następnie proces zastosowany do rzeczywistych obrazów Sgr A* i M87* zrekonstruowanych z obserwacji Teleskopu Horyzontu Zdarzeń dla dwóch czarnych dziur. WYraźnie widać, że dla Sgr A* może zostać wyprodukowanych o wiele więcej obrazów, a statystyka jest bardziej zróżnicowana dla M87*, podczas gdy średnie sąbardzo podobne. Ostatecznie, warto zauważyć, że różne obrazy Sgr A* przedstawiają równie dobre dopasowania do danych obserwacyjnych i nie odnoszą się do różnych momentó czasu jak w filmie poklatkowym (time-lapse).
Źródło:C. M. Fromm (University Würzburg, Germany), L. Rezzolla (University Frankfurt, Germany), EHT Collaboration
O filmie
| Identyfikator: | eso2208-eht-mwj |
| Język: | pl |
| Data publikacji: | 12 maja 2022 15:07 |
| Powiązane komunikaty: | eso2208-eht-mw |
| Czas trwania: | 01 m 30 s |
| Frame rate: | 25 fps |
O obiekcie
| Nazwa: | M87*, Milky Way Galactic Centre |
| Typ: | Milky Way : Galaxy : Component : Central Black Hole Local Universe : Galaxy : Component : Central Black Hole |
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