Image of the Week

 

The power of the third dimension - the discovery of a gigantic cavity in space

 

Figure 1: Three-dimensional view of the Perseus and Taurus molecular clouds, showing the discovered Per-Tau Shell, the gigantic cavity in between the Perseus and Taurus clouds, and the Tau Ring. Image credit: S. Bialy et al. 2021 Astrophysical Journal Letters

 

Looking up from Earth, the stars we see are shown on the canvas of the sky in two dimensions. Though stars or constellations may appear to be close to one another, appearances can be deceiving. With the parallax measurements from Gaia a third dimension is available. Knowing the parallax of a star allows to deduce its distance, which truly allows to pinpoint stars in three-dimensional space.

Let’s focus on a star-forming region near the Perseus and Taurus constellations. Looking at these two constellations, they seem to touch on the sky. But do they really? These constellations are embedded in clouds of dust and interstellar gas, as revealed by infrared observations. What do these clouds reveal of the structure of this star-forming region?

To map molecular clouds in three dimensions is quite complicated though, there are no parallax measurements for these clouds. A new method published today in this paper “On the three-dimensional structure of Local Molecular Clouds” by C. Zucker et al. makes use of the differential dust extinction in the Gaia G-band and converts this to a volume density with the use of a wavelength-dependent extinction curve. This then reveals the shape and thickness of the clouds in its three dimensions.

It is the first time that molecular clouds have been mapped in 3D gas density space, and by doing so, the team of international astronomers have spotted a gigantic cavity in between.

The ApJ Letter “The Per-Tau Shell: A giant star-forming spherical shell revealed by 3D dust observations” by S. Bialy et al. describes this gigantic void in space, which spans nearly 500 light years (over 150 pc in diameter). The research team believes that the cavity was formed by ancient supernovae that went off some 10 million years ago. This sphere-shaped phenomenon may explain how supernovae lead to star formation.

 

“There are many different theories for how gas rearranges itself to form stars,” Catherine Zucker explains. “Astronomers have tested these theoretical ideas using simulations in the past, but this is the first time we can use real — not simulated — 3D views to compare theory to observation, and evaluate which theories work best.”

 

Looking at the image featured here (see Figure 1), we see that while the Perseus and Taurus molecular clouds are touching when viewed from the Sun, there is a clear void in between them when the perspective is changed. They form together a shell around a cavity, now named the Per-Tau Shell. When viewed side-on, a ring-like structure can be seen which is now referred to as the Tau Ring. Observations suggest that there was recent supernova activity within this Per-Tau Shell.

“Hundreds of stars are forming or exist already at the surface of this giant bubble,” says Shmuel Bialy, a postdoctoral researcher at the Institute for Theory and Computation (ITC) at the Center for Astrophysics (CfA) who led the study. “We have two theories—either one supernova went off at the core of this bubble and pushed gas outward forming what we now call the ‘Perseus-Taurus Supershell,’ or a series of supernovae occurring over millions of years created it over time.”

The finding suggests that the Perseus and Taurus molecular clouds are not independent structures in space. But rather, they formed together from the very same supernova shockwave.

“This demonstrates that when a star dies, its supernova generates a chain of events that may ultimately lead to the birth of new stars,” Bialy explains.

 

A visualization with augmented reality is available for these molecular clouds. By scanning the below QR codes, one can look at this 3D map from all directions. More information from this video.

 

 

Video: Using new 3D maps of gas and dust in interstellar space, astronomers have discovered a huge cavity created by a giant supernova explosion 10 million years ago. The same 3D maps, made possible by new statistical techniques applied to data from the Gaia observatory, are revealing the internal structure of dozens of star-forming regions near the Sun, unveiling the 3D nature of star formation in our galaxy, previously hidden in 2D views. Credit: Alyssa Goodman, Jasen Chambers and the Center for Astrophysics | Harvard & Smithsonian.

 

The mapping of these molecular clouds and the discovery of the Per-Tau shell are exciting results of the combined use of Gaia’s Early Data Release 3 and powerful new data science techniques. More exciting results from this area of astronomy are for sure to be expected with future Gaia data releases.

 

"Seeing in 3D with Gaia changes everything", João Alves said, "The region is a small part of the Radcliffe Wave and our results reveal the complexity of its structure at high resolution and the role of feedback on the formation and dispersal of the local interstellar medium."

 

References and further reading:

 

Credits: S. Bialy et al. 2021, C. Zucker et al. 2021

Published: 22/09/2021

 

Image of the Week Archive

2021

24/09: Astrometric microlensing effect in the Gaia16aye event

22/09: the power of the third dimension - the discovery of a gigantic cavity in space

16/09: An alternative Gaia sky chart

25/08: Gaia Photometric Science Alerts and Gravitational Wave Triggers

09/07: How Gaia unveils what stars are made of

23/06: Interviews with CU3

27/04: HIP 70674 Orbital solution resulting from Gaia DR3 processing

30/03: First transiting exoplanet by Gaia

26/03: Apophis' Yarkovsky acceleration improved through stellar occultation

26/02: Matching observations to sources for Gaia DR4

2020

22/12: QSO emission lines in low-resolution BP/RP spectra

03/12: Gaia Early Data Release 3

29/10: Gaia EDR3 passbands

15/10: Star clusters are only the tip of the iceberg

04/09: Discovery of a year long superoutburst in a white dwarf binary

12/08: First calibrated XP spectra

22/07: Gaia and the size of the Solar System

16/07: Testing CDM and geometry-driven Milky Way rotation Curve Models

30/06: Gaia's impact on Solar system science

14/05: Machine-learning techniques reveal hundreds of open clusters in Gaia data

20/03: The chemical trace of Galactic stellar populations as seen by Gaia

09/01: Discovery of a new star cluster: Price-Whelan1

08/01: Largest ever seen gaseous structure in our Galaxy

2019
20/12: The lost stars of the Hyades
06/12: Do we see a dark-matter like effect in globular clusters?
12/11: Hypervelocity star ejected from a supermassive black hole
17/09: Instrument Development Award
08/08: 30th anniversary of Hipparcos
17/07: Whitehead Eclipse Avoidance Manoeuvre
28/06: Following up on Gaia Solar System Objects
19/06: News from the Gaia Archive
29/05: Spectroscopic variability of emission lines stars with Gaia
24/05: Evidence of new magnetic transitions in late-type stars
03/05: Atmospheric dynamics of AGB stars revealed by Gaia
25/04: Geographic contributions to DPAC
22/04: omega Centauri's lost stars
18/04: 53rd ESLAB symposium "the Gaia universe"
18/02: A river of stars
2018
21/12: Sonification of Gaia data
18/12: Gaia captures a rare FU Ori outburst
12/12: Changes in the DPAC Executive
26/11:New Very Low Mass dwarfs in Gaia data
19/11: Hypervelocity White Dwarfs in Gaia data
15/11: Hunting evolved carbon stars with Gaia RP spectra
13/11: Gaia catches the movement of the tiny galaxies surrounding the Milky Way
06/11: Secrets of the "wild duck" cluster revealed
12/10: 25 years since the initial GAIA proposal
09/10: 3rd Gaia DPAC Consortium Meeting
30/09: A new panoramic sky map of the Milky Way's Stellar Streams
25/09: Plausible home stars for interstellar object 'Oumuamua
11/09: Impressions from the IAU General Assembly
30/06: Asteroids in Gaia Data
14/06: Mapping and visualising Gaia DR2

25/04: In-depth stories on Gaia DR2

14/04: Gaia tops one trillion observations
16/03: Gaia DR2 Passbands
27/02: Triton observation campaign
11/02: Gaia Women In Science
29/01: Following-up on Gaia
2017
19/12: 4th launch anniversary
24/11: Gaia-GOSA service
27/10: German Gaia stamp in the making
19/10: Hertzsprung-russell diagram using Gaia DR1
05/10: Updated prediction to the Triton occultation campaign
04/10: 1:1 Gaia model arrives at ESAC
31/08: Close stellar encounters from the first Gaia data release
16/08: Preliminary view of the Gaia sky in colour
07/07: Chariklo stellar occultation follow-up
24/04: Gaia reveals the composition of asteroids
20/04: Extra-galactic observations with Gaia
10/04: How faint are the faintest Gaia stars?
24/03: Pulsating stars to study Galactic structures
09/02: Known exoplanetary transits in Gaia data
31/01: Successful second DPAC Consortium Meeting
2016
23/12: Interactive and statistical visualisation of Gaia DR1 with vaex
16/12: Standard uncertainties for the photometric data (in GDR1)
25/11: Signature of the rotation of the galactic bar uncovered
15/11: Successful first DR1 Workshop
27/10: Microlensing Follow-Up
21/10: Asteroid Occultation
16/09: First DR1 results
14/09: Pluto Stellar Occultation
15/06: Happy Birthday, DPAC!
10/06: 1000th run of the Initial Data Treatment system
04/05: Complementing Gaia observations of the densest sky regions
22/04: A window to Gaia - the focal plane
05/04: Hipparcos interactive data access tool
24/03: Gaia spots a sunspot
29/02: Gaia sees exploding stars next door
11/02: A new heart for the Gaia Object Generator
04/02: Searching for solar siblings with Gaia
28/01: Globular cluster colour-magnitude diagrams
21/01: Gaia resolving power estimated with Pluto and Charon
12/01: 100th First-Look Weekly Report
06/01: Gaia intersects a Perseid meteoroid
2015
18/12: Tales of two clusters retold by Gaia
11/11: Lunar transit temperature plots
06/11: Gaia's sensors scan a lunar transit
03/11: Celebrity comet spotted among Gaia's stars
09/10: The SB2 stars as seen by Gaia's RVS
02/10: The colour of Gaia's eyes
24/09: Estimating distances from parallaxes
18/09: Gaia orbit reconstruction
31/07: Asteroids all around
17/07: Gaia satellite and amateur astronomers spot one in a billion star
03/07: Counting stars with Gaia
01/07: Avionics Model test bench arrives at ESOC
28/05: Short period/faint magnitude Cepheids in the Large Magellanic Cloud
19/05: Visualising Gaia Photometric Science Alerts
09/04: Gaia honours Einstein by observing his cross
02/04: 1 April - First Look Scientists play practical joke
05/03: RR Lyrae stars in the Large Magellanic Cloud as seen by Gaia
26/02: First Gaia BP/RP deblended spectra
19/02: 13 months of GBOT Gaia observations
12/02: Added Value Interface Portal for Gaia
04/02: Gaia's potential for the discovery of circumbinary planets
26/01: DIBs in three hot stars as seen by Gaia's RVS
15/01: The Tycho-Gaia Astrometric Solution
06/01: Close encounters of the stellar kind
2014
12/12: Gaia detects microlensing event
05/12: Cat's Eye Nebula as seen by Gaia
01/12: BFOSC observation of Gaia at L2
24/11: Gaia spectra of six stars
13/11: Omega Centauri as seen by Gaia
02/10: RVS Data Processing
12/09: Gaia discovers first supernova
04/08: Gaia flag arrives at ESAC
29/07: Gaia handover
15/07: Eclipsing binaries
03/07: Asteroids at the "photo finish"
19/06: Calibration image III - Messier 51
05/06: First Gaia BP/RP and RVS spectra
02/06: Sky coverage of Gaia during commissioning
03/04: Gaia source detection
21/02: Sky-background false detections in the sky mapper
14/02: Gaia calibration images II
06/02: Gaia calibration image I
28/01: Gaia telescope light path
17/01: First star shines for Gaia
14/01: Radiation Campaign #4
06/01: Asteroid detection by Gaia
2013
17/12: Gaia in the gantry
12/12: The sky in G magnitude
05/12: Pre-launch release of spectrophotometric standard stars
28/11: From one to one billion pixels
21/11: The Hipparcos all-sky map
15/10: Gaia Sunshield Deployment Test
08/10: Initial Gaia Source List
17/09: CU1 Operations Workshop
11/09: Apsis
26/08: Gaia arrival in French Guiana
20/08: Gaia cartoons
11/07: Model Soyuz Fregat video
01/07: Acoustic Testing
21/06: SOVT
03/06: CU4 meeting #15
04/04: DPCC (CNES) 
26/03: Gaia artist impression 
11/02: Gaia payload testing  
04/01: Space flyby with Gaia-like data
2012
10/12: DPAC OR#2. Testing with Planck
05/11: Galaxy detection with Gaia
09/10: Plot of part of the GUMS-10 catalogue
23/07: "Gaia" meets at Gaia
29/06: The Sky as seen by Gaia
31/05: Panorama of BAM clean room
29/03: GREAT school results
12/03: Scanning-law movie
21/02: Astrometric microlensing and Gaia
03/02: BAM with PMTS
12/01: FPA with all the CCDs and WFSs
2011
14/12: Deployable sunshield
10/11: Earth Trojan search
21/10: First Soyuz liftoff from the French Guiana
20/09: Fast 2D image reconstruction algorithm
05/09: RVS OMA
10/08: 3D distribution of the Gaia catalogue
13/07: Dynamical Attitude Model
22/06: Gaia's view of open clusters
27/05: Accuracy of the stellar transverse velocity
13/05: Vibration test of BAM mirrors
18/04: L. Lindegren, Dr. Honoris Causa of the Observatory of Paris
19/01: Detectability of stars close to Jupiter
05/01: Delivery of the WFS flight models
2010
21/12: The 100th member of CU3
17/11: Nano-JASMINE and AGIS
27/10: Eclipsing binary light curves fitted with DPAC code
13/10: Gaia broad band photometry
28/09: Measuring stellar parameters and interstellar extinction
14/09: M1 mirror
27/08: Quest for the Sun's siblings
 
Please note: Entries from the period 2003-2010 are available in this PDF document.