Γαλαξιακή «βέρα» νέων άστρων, Golden rings of star formation

Το Hubble φωτογράφισε τα «χρυσά δαχτυλίδια» του γαλαξία NGC 3081. Taking center stage in this new NASA/ESA Hubble Space Telescope image is a galaxy known as NGC 3081, set against an assortment of glittering galaxies in the distance. Located in the constellation of Hydra (The Sea Serpent), NGC 3081 is located over 86 million light-years from us. It is known as a type II Seyfert galaxy, characterized by its dazzling nucleus. NGC 3081 is seen here nearly face-on. Compared to other spiral galaxies, it looks a little different. The galaxy's barred spiral center is surrounded by a bright loop known as a resonance ring. This ring is full of bright clusters and bursts of new star formation, and frames the supermassive black hole thought to be lurking within NGC 3081 — which glows brightly as it hungrily gobbles up in-falling material. These rings form in particular locations known as resonances, where gravitational effects throughout a galaxy cause gas to pile up and accumulate in certain positions. These can be caused by the presence of a "bar" within the galaxy, as with NGC 3081, or by interactions with other nearby objects. It is not unusual for rings like this to be seen in barred galaxies, as the bars are very effective at gathering gas into these resonance regions, causing pile-ups which lead to active and very well-organized star formation. Hubble snapped this magnificent face-on image of the galaxy using the Wide Field Planetary Camera 2. This image is made up of a combination of ultraviolet, optical, and infrared observations, allowing distinctive features of the galaxy to be observed across a wide range of wavelengths. Credit: ESA/Hubble & NASA. Acknowledgement: R. Buta (University of Alabama)

Μια ακόμη εντυπωσιακή ανακάλυψη προσέθεσε στον πλούσιο παλμαρέ του το διαστημικό τηλεσκόπιο Hubble. Παρατηρώντας τον γαλαξία NGC 3081 που βρίσκεται σε απόσταση 86 εκ. έτη φωτός από τη Γη εντόπισε και φωτογράφισε μια εντυπωσιακή κοσμική δομή που υπάρχει σε αρκετούς γαλαξίες αλλά δεν είχε επιτευχθεί μέχρι σήμερα η λεπτομερής καταγραφή του.

Color composite image of the spiral galaxy NGC 3081, showing the bright ring of star formation around the weak bar. Note the background galaxies to the lower left of center that are being seen through NGC 3081. The small, bluish color-objects in the ring are clusters of massive and very young stars. Notice how these young stars and clusters congregate near the ends of the ellipse. Because of the great distance (106 million light years), the young star clusters are almost star-like in appearance. Credit: R. Buta, G. Byrd, and T. Freeman

Γύρω από τον γαλαξία έχει σχηματιστεί ένας γιγάντιος δακτύλιος που αποτελεί σύμφωνα με τους επιστήμονες ένα τεράστιο εργοστάσιο παραγωγής νέων άστρων. Στην πραγματικότητα πρόκειται για πολλούς δακτυλίους που φαίνονται στις εικόνες που τράβηξε ο Hubble ως ένας. Οι ειδικοί προσέδωσαν στους δακτυλίους του NGC 3081 τον χαρακτηρισμό «Χρυσά Δαχτυλίδια Γέννησης Άστρων».