Spectroastrometry of rotating gas disks for the detection of supermassive black holes in galactic nuclei

Gnerucci, Alessio; Marconi, A.; Capetti, A.; Axon, D. J.; Robinson, Andrew

doi:10.1051/0004-6361/200912530

Cited by 19 publications

(36 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We neglect all hydrodynamical effects, therefore the disk motion is entirely determined by the gravitational potential. The model also includes the effect of beam smearing (for details, see Gnerucci et al 2010Gnerucci et al , 2011. The central panel of Fig.…”

Section: [Cii] Velocity Analysismentioning

confidence: 99%

ALMA resolves turbulent, rotating [CII] emission in a young starburst galaxy atz= 4.8

Breuck

Williams

Swinbank

et al. 2014

A&A

123

136

View full text Add to dashboard Cite

We present spatially resolved Atacama Large Millimeter/submillimeter Array (ALMA) [Cii] observations of the z = 4.7555 submillimetre galaxy, ALESS 73.1. Our 0. 5 FWHM map resolves the [Cii] emitting gas which is centred close to the active galactic nucleus (AGN). The gas kinematics are dominated by rotation but with high turbulence, v rot /σ int ∼ 3.1, and a Toomre Q parameter <1 throughout the disk. By fitting three independent thin rotating disk models to our data, we derive a total dynamical mass of 3 ± 2 × 10 10 M . This is close to the molecular gas mass derived from previous CO(2-1) observations, and implies a CO to H 2 conversion factor α CO < 2.3 M (K km s −1 pc 2 ) −1 . The mass budget also constrains the stellar mass to <3.1 × 10 10 M , and entails a gas fraction of f gas 0.4. The diameter of the dust continuum emission is <2 kpc, while the star-formation rate is as high as 1000 M yr −1 . Combined with our stellar mass constraint, this implies an extreme specific star formation rate >80 Gyr −1 , especially since there are no clear indications of recent merger activity. Finally, our high signal-to-noise [Cii] measurement revises the observed [Nii]/[Cii] ratio, which suggests a close to solar metallicity, unless the [Cii] flux contains significant contributions from Hii regions. Our observations suggest that ALESS73.1 is a nascent galaxy undergoing its first major burst of star formation, embedded within an unstable but metal-rich gas disk.

show abstract

Section: [Cii] Velocity Analysismentioning

confidence: 99%

ALMA resolves turbulent, rotating [CII] emission in a young starburst galaxy atz= 4.8

Breuck

Williams

Swinbank

et al. 2014

A&A

123

136

View full text Add to dashboard Cite

show abstract

“…Accuracies of milli-arcsec can be achieved in natural seeing. Gnerucci et al (2010) developed an application of spectroastrometry for measuring the masses of Black Holes and extended this (Gnerucci et al 2011a) to galaxy discs in IFS measurements. The technique here now involves the measurement of the position centroid (now in 2D) of the blue vs. red half of an emission line as defined by the integrated spectrum and mean wavelength.…”

Section: Dynamical Massesmentioning

confidence: 99%

The Dawes Review 1: Kinematic Studies of Star-Forming Galaxies Across Cosmic Time

Glazebrook

2013

Publ. Astron. Soc. Aust.

137

View full text Add to dashboard Cite

The last seven years have seen an explosion in the number of Integral Field galaxy surveys, obtaining resolved 2D spectroscopy, especially at high-redshift. These have taken advantage of the mature capabilities of 8-10 m class telescopes and the development of associated technology such as AO. Surveys have leveraged both high spectroscopic resolution enabling internal velocity measurements and high spatial resolution from AO techniques and sites with excellent natural seeing. For the first time, we have been able to glimpse the kinematic state of matter in young, assembling starforming galaxies and learn detailed astrophysical information about the physical processes and compare their kinematic scaling relations with those in the local Universe. Observers have measured disc galaxy rotation, merger signatures, and turbulence-enhanced velocity dispersions of gas-rich discs. Theorists have interpreted kinematic signatures of galaxies in a variety of ways (rotation, merging, outflows, and feedback) and attempted to discuss evolution vs. theoretical models and relate it to the evolution in galaxy morphology. A key point that has emerged from this activity is that substantial fractions of high-redshift galaxies have regular kinematic morphologies despite irregular photometric morphologies and this is likely due to the presence of a large number of highly gas-rich discs. There has not yet been a review of this burgeoning topic. In this first Dawes review, I will discuss the extensive kinematic surveys that have been done and the physical models that have arisen for young galaxies at high-redshift.

show abstract

“…In this paper we present an alternative to the classical virial mass estimate based on the technique of spectroastrometry with the aim of obtaining a more accurate dynamical mass estimator. We follow up on the work of Gnerucci et al (2010) about the application of the spectroastrometry technique to the study of the dynamics of rotating gas disks. This paper is based on the data pertaining to two projects focussed on studying metallicity and dynamics of high-redshift galaxies: AMAZE (Assessing the Mass-Abundance redshift Evolution) (Maiolino et al 2008a,b) and LSD (Lyman-break galaxies Stellar populations and Dynamics) (Mannucci & Maiolino 2008;Mannucci et al 2009).…”

Section: Introductionmentioning

confidence: 99%

A dynamical mass estimator for highzgalaxies based on spectroastrometry

Gnerucci

Marconi

Cresci

et al. 2011

A&A

Self Cite

View full text Add to dashboard Cite

Galaxy dynamical masses are important physical quantities to constrain galaxy evolutionary models, especially at high redshifts. However, at z 2 the limited signal to noise ratio and spatial resolution of the data usually do not allow spatially resolved kinematical modeling and very often only virial masses can be estimated from line widths. But even such estimates require a good knowledge of galaxy size, which may be smaller than the spatial resolution. Spectroastrometry is a technique which combines spatial and spectral resolution to probe spatial scales significantly smaller than the spatial resolution of the observations. Here we apply it to the case of high-z galaxies and present a method based on spectroastrometry to estimate dynamical masses of high z galaxies, which overcomes the problem of size determination with poor spatial resolution. We construct and calibrate a "spectroastrometric" virial mass estimator, modifying the "classical" virial mass formula. We apply our method to the [O III] or Hα emission line detected in z ∼ 2−3 galaxies from AMAZE, LSD and SINS samples and we compare the spectroastrometric estimator with dynamical mass values resulting from full spatially resolved kinematical modeling. The spectroastrometric estimator is found to be a good approximation of dynamical masses, presenting a linear relation with a residual dispersion of only 0.15 dex. This is a big improvement compared to the "classical" virial mass estimator which has a non linear relation and much larger dispersion (0.47 dex) compared to dynamical masses. By applying our calibrated estimator to 16 galaxies from the AMAZE and LSD samples, we obtain masses in the ∼10 7 −10 10 M range extending the mass range attainable with dynamical modeling.

show abstract

Spectroastrometry of rotating gas disks for the detection of supermassive black holes in galactic nuclei

Cited by 19 publications

References 10 publications

ALMA resolves turbulent, rotating [CII] emission in a young starburst galaxy atz= 4.8

ALMA resolves turbulent, rotating [CII] emission in a young starburst galaxy atz= 4.8

The Dawes Review 1: Kinematic Studies of Star-Forming Galaxies Across Cosmic Time

A dynamical mass estimator for highzgalaxies based on spectroastrometry

Contact Info

Product

Resources

About