A new distance to the Brick, the dense molecular cloud G0.253+0.016

Abstract

We analyse the near infrared colour magnitude diagram of a field including the giant molecular cloud G0.253+0.016 (a.k.a. The Brick) observed at high spatial resolution, with HAWK-I at the VLT. The distribution of red clump stars in a line of sight crossing the cloud, compared with that in a direction just beside it, and not crossing it, allow us to measure the distance of the cloud from the Sun to be 7.20, with a statistical uncertainty of +/-0.16 and a systematic error of +/-0.20 kpc. This is significantly closer than what is generally assumed, i.e., that the cloud belongs to the near side of the central molecular zone, at 60 pc from the Galactic center. This assumption was based on dynamical models of the central molecular zone, observationally constrained uniquely by the radial velocity of this and other clouds. Determining the true position of the Brick cloud is relevant because this is the densest cloud of the Galaxy not showing any ongoing star formation. This puts the cloud off by 1 order of magnitude from the Kennicutt-Schmidt relation between the density of the dense gas and the star formation rate. Several explanations have been proposed for this absence of star formation, most of them based on the dynamical evolution of this and other clouds, within the Galactic center region. Our result emphasizes the need to include constraints coming from stellar observations in the interpretation of our Galaxy central molecular zone.

7 pages, 4 figures. Accepted for publication in MNRAS

References in corpus (13)

• A multi-transition HCN and HCO+ study of 12 nearby active galaxies: AGN versus SB environments
• The dynamical evolution of molecular clouds near the Galactic Centre - I. Orbital structure and evolutionary timeline
• A SINFONI view of Galaxy Centers: Morphology and Kinematics of five Nuclear Star Formation Rings
• 'The Brick' is not a brick: A comprehensive study of the structure and dynamics of the Central Molecular Zone cloud G0.253+0.016
• The Milky Way's nuclear star cluster: Old, metal-rich, and cuspy
• Extinction ratios in the inner Galaxy as revealed by the VVV survey
• Dense gas is not enough: environmental variations in the star formation efficiency of dense molecular gas at 100pc scales in M51
• CMZoom: Survey Overview and First Data Release
• The Quintuplet Cluster III. Hertzsprung-Russell diagram and cluster age
• Isolated massive stars in the Galactic center: The dynamic contribution from the Arches and Quintuplet star clusters
• Proper motions in the VVV Survey: Results for more than 15 million stars across NGC 6544
• GALACTICNUCLEUS: A high-angular-resolution JHKs imaging survey of the Galactic centre III. Evidence for wavelength dependence of the extinction curve in the near-infrared
• Using classical Cepheids to study the far side of the Milky Way disk: I. Spectroscopic classification and the metallicity gradient

Cited by in corpus (7)

• Star formation in 'the Brick': ALMA reveals an active proto-cluster in the Galactic centre cloud G0.253+0.016
• Distance to three molecular clouds in the central molecular zone
• 3-D CMZ IV: Distinguishing Near vs. Far Distances in the Galactic Center Using Spitzer and Herschel
• Galactic center gamma-ray production by cosmic rays from stellar winds and Sgr A East
• Distance to the Brick cloud using stellar kinematics
• 3D CMZ V: A new orbital model of our Galaxy's Center, informed by data across the electromagnetic spectrum
• Self-consistent modelling of the Milky Way's Nuclear Stellar Disc