Hubble observes Jets, bubbles, and bursts of light in Taurus

The NASA/ESA Hubble Space Telescope has snapped a striking view of a multiple star system called XZ Tauri, its neighbour HL Tauri and several nearby young stellar objects. 

XZ Tauri is blowing a hot bubble of gas into the surrounding space, which is filled with bright and beautiful clumps that are emitting strong winds and jets. 

These objects illuminate the region, creating a truly dramatic scene. 

Credit: ESA/Hubble/ NASA

The NASA/ESA Hubble Space Telescope has snapped a striking view of a multiple star system called XZ Tauri, its neighbour HL Tauri, and several nearby young stellar objects.

XZ Tauri is blowing a hot bubble of gas into the surrounding space, which is filled with bright and beautiful clumps that are emitting strong winds and jets.

These objects illuminate the region, creating a truly dramatic scene.

This dark and ominous landscape is located some 450 light-years away in the constellation of Taurus (The Bull).

It lies in the north-eastern part of a large, dark cloud known as LDN 1551.

Just to the left of centre in this image, embedded within a rust-coloured cloud, lies XZ Tauri. While it appears to be a single star, this bright spot actually consists of several stars.

It has long been known to be a binary, but one of these two stars is thought also to be a binary, making a total of three stars within a single system.

This is not the first time that Hubble has observed XZ Tauri, between the years of 1995 and 2000, a hot bubble of gas was spotted expanding outwards from the system.

This bubble can be seen as the small orange lobe very close to the top left of XZ Tauri. This gas is speeding out from the star system, leaving a trail spanning tens of billions of kilometres.

As the bubble travels it hits slower moving material, triggering pulses of light and rippling shockwaves.

Above and to the right of XZ Tauri, an equally epic scene is unfolding. Wisps of deep red seem to be streaking away from the blue-tinged clumps on the right.

This bright blue patch contains a star known as HL Tauri, which is associated with Herbig-Haro object HH 150.

Herbig-Haro objects are streaks of hot gas blasted into space by newborn and newly forming stars and LDN 1551 is particularly rich in these dramatic objects.

In the bottom right of this Hubble image is another Herbig-Haro object known as HH 30, associated with the variable star V1213 Tauri.

The star itself is hidden within a flat, bright disc of dust that is split in half by a dark lane. This dust blocks direct light from V1213 Tauri, but the star is visible via its reflected light and the prominent, knotty jets it is blasting out into space.

Hubble previously viewed HH 30, alongside XZ Tauri, with its Wide Field Planetary Camera 2 between the years of 1995 and 2000.

The observations were used to image and study the changes in disc brightness and jet strength over the five-year period.

V1213 Tauri's strong magnetic field forms the jets by funnelling and shepherding gas from the disc, accelerating it along the star's magnetic poles to form two narrow beams.

ALMA image of the young star HL Tau and its protoplanetary disk. 

This best image ever of planet formation reveals multiple rings and gaps that herald the presence of emerging planets as they sweep their orbits clear of dust and gas 

Credit: ALMA (NRAO /ESO /NAOJ); C. Brogan, B. Saxton (NRAO /AUI /NSF)

In the above image released by the European Southern Observatory today, observations from the Atacama Large Millimeter /submillimeter Array (ALMA) reveal extraordinarily fine and never-before-seen detail in the planet-forming disc around HL Tauri.

The new observations are an enormous step forward in the observation of how protoplanetary discs develop and how planets form.

Hubble finds jets and explosions in NGC 7793

Credit: ESA /Hubble & NASA, Acknowledgement: D. Calzetti (University of Massachusetts) and the LEGUS Team

This new image from the NASA/ESA Hubble Space Telescope shows NGC 7793, a spiral galaxy in the constellation of Sculptor some 13 million light-years away from Earth.

NGC 7793 is one of the brightest galaxies in the Sculptor Group, one of the closest groups of galaxies to the Local Group, the group of galaxies containing our galaxy, the Milky Way and the Magellanic Clouds.

The image shows NGC 7793's spiral arms and small central bulge.

Unlike some other spirals, NGC 7793 doesn't have a very pronounced spiral structure, and its shape is further muddled by the mottled pattern of dark dust that stretches across the frame.

The occasional burst of bright pink can be seen in the galaxy, highlighting stellar nurseries containing newly-forming baby stars.

Although it may look serene and beautiful from our perspective, this galaxy is actually a very dramatic and violent place.

Astronomers have discovered a powerful micro-quasar within NGC 7793, a system containing a black hole actively feeding on material from a companion star.

A micro-quasar is an object that has some of the properties of quasars in miniature. While many full-sized quasars are known at the cores of other galaxies, it is unusual to find a quasar in a galaxy's disk rather than at its center.

Micro-quasars are almost like scale models, they allow astronomers to study quasars in detail. As material falls inwards towards this black hole, it creates a swirling disk around it.

Some of the infalling gas is propelled violently outwards at extremely high speeds, creating jets streaking out into space in opposite directions.

In the case of NGC 7793, these jets are incredibly powerful, and are in the process of creating an expanding bubble of hot gas some 1,000 light-years across.

ALMA probes mysteries of jets from giant black holes

This detailed view shows the central parts of the nearby active galaxy NGC 1433. 

The dim blue background image, showing the central dust lanes of this galaxy, comes from the NASA/ESA Hubble Space Telescope. 

The coloured structures near the centre are from recent ALMA observations that have revealed a spiral shape, as well as an unexpected outflow, for the first time. 

Credit: ALMA (ESO/NAOJ/NRAO)/NASA/ESA/F. Combes

Two international teams of astronomers have used the power of the Atacama Large Millimeter/submillimeter Array to focus on jets from the huge black holes at the centers of galaxies and observe how they affect their surroundings.

They have respectively obtained the best view yet of the molecular gas around a nearby, quiet black hole and caught an unexpected glimpse of the base of a powerful jet close to a distant black hole.

There are supermassive black holes—with masses up to several billion solar masses—at the hearts of almost all galaxies in the Universe, including our own galaxy, the Milky Way.

In the remote past, these bizarre objects were very active, swallowing enormous quantities of matter from their surroundings, shining with dazzling brilliance, and expelling tiny fractions of this matter through extremely powerful jets.

In the current Universe, most supermassive black holes are much less active than they were in their youth, but the interplay between jets and their surroundings is still shaping galaxy evolution.

Two new studies, both published today in the journal Astronomy & Astrophysics, used ALMA to probe black hole jets at very different scales: a nearby and relatively quiet black hole in the galaxy NGC 1433 and a very distant and active object called PKS 1830-211.

Françoise Combes

"ALMA has revealed a surprising spiral structure in the molecular gas close to the centre of NGC 1433," says Françoise Combes (Observatoire de Paris, France), who is the lead author of the first paper.

"This explains how the material is flowing in to fuel the black hole. With the sharp new observations from ALMA, we have discovered a jet of material flowing away from the black hole, extending for only 150 light-years. This is the smallest such molecular outflow ever observed in an external galaxy."

The discovery of this outflow, which is being dragged along by the jet from the central black hole, shows how such jets can stop star formation and regulate the growth of the central bulges of galaxies.

Ivan Marti-Vidal

In PKS 1830-211, Ivan Marti-Vidal (Chalmers University of Technology, Onsala Space Observatory, Onsala, Sweden) and his team also observed a supermassive black hole with a jet, but a much brighter and more active one in the early Universe.

It is unusual because its brilliant light passes a massive intervening galaxy on its way to Earth, and is split into two images by gravitational lensing.

From time to time, supermassive black holes suddenly swallow a huge amount of mass, which increases the power of the jet and boosts the radiation up to the very highest energies.

Now ALMA has, by chance, caught one of these events as it happens in PKS 1830-211.

More information: These research projects are presented in two papers, "ALMA observations of feeding and feedback in nearby Seyfert galaxies: an AGN-driven outflow in NGC1433", by F. Combes et al. and "Probing the jet base of the blazar PKS 1830−211 from the chromatic variability of its lensed images: Serendipitous ALMA observations of a strong gamma-ray flare, by I. Marti-Vidal et al. Both papers are appeared in the journal Astronomy & Astrophysics.