Using the NIRCam and MIRI instruments onboard the NASA/ESA/CSA James Webb Space Telescope, astronomers have produced a high-resolution image of Herbig-Haro object 49/50 (HH 49/50), which is located about 630 light-years away in the constellation of Chamaeleon.
Webb observed Herbig-Haro 49/50 in high-resolution near- and mid-infrared light with the NIRCam and MIRI instruments. Image credit: NASA / ESA / CSA / STScI.
Herbig-Haro objects are small bright patches of nebulosity associated with protostars in star-forming regions.
These structures were first observed in the 19th century by the American astronomer Sherburne Wesley Burnham, but were not recognized as being a distinct type of emission nebula until the 1940s.
The first astronomers to study them in detail were George Herbig and Guillermo Haro, after whom they have been named.
Herbig-Haro objects are formed under very specific circumstances — when hot gas ejected by a newborn star collides with the gas and dust around it at speeds of up to 250,000 kmh (155,000 mph), creating bright shock waves.
They come in a wide array of shapes, the basic configuration is usually the same: twin jets of heated gas, ejected in opposite directions from a forming star, stream through interstellar space.
“When NASA’s Spitzer Space Telescope observed it in 2006, scientists nicknamed HH 49/50 the Cosmic Tornado for its helical appearance, but they were uncertain about the nature of the fuzzy object at the tip of the ‘tornado’,” said Webb astronomers in a statement.
“With its higher imaging resolution, Webb provides a different visual impression of HH 49/50 by revealing fine features of the shocked regions in the outflow, uncovering the fuzzy object to be a distant spiral galaxy, and displaying a sea of distant background galaxies.”
HH 49/50 is part of the Chamaeleon I Cloud complex, one of the nearest active star-forming regions.
“This cloud complex is likely similar to the environment that our Sun formed in,” the astronomers said.
“Past observations of this region show that the HH 49/50 outflow is moving away from us at speeds of 100-300 km per second and is just one feature of a larger outflow.”
“Webb’s NIRCam and MIRI observations of HH 49/50 trace the location of glowing hydrogen molecules, carbon monoxide molecules, and energised grains of dust, represented in orange and red, as the protostellar jet slams into the region.”
The new Webb observations probe details on small spatial scales that will help astronomers to model the properties of the jet and understand how it is affecting the surrounding material.
“The arc-shaped features in HH 49/50, similar to a water wake created by a speeding boat, point back to the source of this outflow,” the researchers said.
“Based on past observations, scientists suspect that a protostar known as Cederblad 110 IRS4 is a plausible driver of the jet activity.”
“Located roughly 1.5 light-years away from HH 49/50, CED 110 IRS4 is a Class I protostar.”
“Class I protostars are young objects (tens of thousands to a million years old) in the prime time of gaining mass.”
“They usually have a discernible disk of material surrounding it that is still falling onto the protostar. “
“Scientists recently used Webb’s NIRCam and MIRI observations to study this protostar and obtain an inventory of the icy composition of its environment.”
“These detailed Webb images of the arcs in HH 49/50 can more precisely pinpoint the direction to the jet source, but not every arc points back in the same direction.”
“For example, there is an interesting outcrop feature (at the top right of the main outflow) which could be another chance superposition of a different outflow, related to the slow precession of the intermittent jet source.”
“Alternatively, this feature could be a result of the main outflow breaking apart.”
“The galaxy that appears by happenstance at the tip of HH 49/50 is a much more distant, face-on spiral galaxy.”
“It has a prominent central bulge represented in blue that shows the location of older stars.”
“The bulge also shows hints of side lobes suggesting that this could be a barred-spiral galaxy.”
“Reddish clumps within the spiral arms show the locations of warm dust and groups of forming stars.”
“The galaxy even displays evacuated bubbles in these dusty regions, similar to nearby galaxies observed by Webb as part of the PHANGS program.”
“Webb has captured these two unassociated objects in a lucky alignment.”
“Over thousands of years, the edge of HH 49/50 will move outwards and eventually appear to cover up the distant galaxy.”
