Three-Dimensional Distribution of the ISM in the Milky Way Galaxy: II. The Molecular Gas Disk

By H. Nakanishi, Y. Sofue. 2006

183 citations recorded by the source corpus.

We created a three-dimensional distribution map of molecular gas throughout the Milky Way galaxy using the latest 12 CO (J =1–0) survey data cube and the rotation curve based on the kinematic distance. The radial distribution of the molecular gas shows a central peak and a second peak around 0.5 R0 (R0: the solar Galactocentric distance). The thickness of the molecular disk slightly increases from 48pc to 160pc with the Galactocentric distance within a radius range of 0–11kpc. We were able to trace the Outer, the Perseus, the Sagittarius–Carina, the Scutum–Crux, and the Norma arms as logarithmic spiral arms with pitch angles of 11 ◦ –15 ◦ . Considering that the pitch angles of the spiral arms are within this range, the Norma and the Outer arms seem to be identified as the same spiral arm. We could also trace a midplane displacement, whose amplitude is nearly constant inside a 10kpc radius and increases beyond this radius. The ridges of the midplane displacement form the leading spiral arms.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/8d69141505d2ccb84c804f8961d90c974ba29010

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Citations in the corpus

• STAR FORMATION RELATIONS IN NEARBY MOLECULAR CLOUDS (2014, background): “…in context, we note that the Sun lies in a part of the Galactic disk in which the gas surface density is dominated by atomic gas (Σatomic ∼ 10 M⊙ pc −2), while the smoothed out surface density of molecular gas is much less (Σmol ∼ 1 M⊙ pc−2) (Dame et al. 2001, Nakanishi and Sofue 2006).”
• Star Formation in the Milky Way and Nearby Galaxies (2012, methodology): “Inside about 13 kpc, the atomic surface density is roughly constant at 10-15 M⊙ pc −2, while the average molecular surface density increases sharply, passing 1 M⊙ pc −2 somewhere near the solar neighborhood (Dame et al. 2001), to a local maximum around Rgal = 4-5 kpc (Nakanishi & Sofue 2006).”
• REGULATION OF STAR FORMATION RATES IN MULTIPHASE GALACTIC DISKS: A THERMAL/DYNAMICAL EQUILIBRIUM MODEL (2010, background): “…and Wolfire et al. 2003), ρsd = 0.05 M⊙ pc −3 (Holmberg & Flynn 2000), and ΣGBC <∼ 2 M⊙ pc−2 (Dame et al. 1987, 2001; Bronfman et al. 1988; Luna et al. 2006; Nakanishi & Sofue 2006) near the Sun, the result from equation (10) is consistent with the observed total surface density estimate ∼ 10 M⊙…”
• Toward First-Principle Simulations of Galaxy Formation: I. How Should We Choose Star-Formation Criteria in High-Resolution Simulations of Disk Galaxies? (2008, methodology): “Note that the truncation radius, Rtrunc = 10.5 kpc, is close to the edge of the molecular disk in the Milky Way galaxy (∼ 11 kpc; Nakanishi & Sofue 2006).”
• Unified Rotation Curve of the Galaxy — Decomposition into de Vaucouleurs Bulge, Disk, Dark Halo, and the 9-kpc Rotation Dip — (2008, methodology): “Since the observed data are obtained for stars and gas within several kpc from the Sun, it is possible that this ring represents a density wave corresponding to the Perseus Arm (e.g. Nakanishi and Sofue 2003, 2006).”
• The RMS survey : Galactic distribution of massive star formation (2013, methodology): “We include the H2 gas surface density derived from CO observations (Nakanishi & Sofue 2006) in Fig.”
• The ATLAS3D project - XIV. The extent and kinematics of the molecular gas in early-type galaxies (2012, result): “We give the molecular gas disk/rings a fixed vertical scale height of 100pc, similar to that observed in the Milky Way (e.g. Nakanishi & Sofue 2006, using any sensible value of this parameter does not change our results).”
• The observed spiral structure of the Milky Way (2014, background): “The spiral structure derived from diffuse HI and CO distributions is far from clear at present (e.g., see Nakanishi & Sofue 2003, 2006).”
• GALACTOSEISMOLOGY: DISCOVERY OF VERTICAL WAVES IN THE GALACTIC DISK (2012, background): “(For observational evidence of m = 0 modes or midplane displacement in the molecular gas distribution of the Galaxy, see Nakanishi & Sofue (2006).)”
• TRIGONOMETRIC PARALLAXES OF MASSIVE STAR-FORMING REGIONS. VI. GALACTIC STRUCTURE, FUNDAMENTAL PARAMETERS, AND NONCIRCULAR MOTIONS (2009, background): “…the number of spiral arms in the Galaxy (Simonson 1976; Bash 1981; Vallée 1995; Drimmel 2000; Drimmel & Spergel 2001; Benjamin et al. 2005; Nakanishi & Sofue 2006; Steiman-Camerson, Wolfire & Hollenbach 2008), with Spitzer GLIMPSE survey results suggesting only two arms can be traced in…”
• FERMI OBSERVATIONS OF CASSIOPEIA AND CEPHEUS: DIFFUSE GAMMA-RAY EMISSION IN THE OUTER GALAXY (2009, methodology): “12 between the γ-ray estimates of XCO and the XCO(R) function by Nakanishi & Sofue (2006) which relies on virial masses.”
• PHYSICAL PROPERTIES OF MOLECULAR CLOUDS FOR THE ENTIRE MILKY WAY DISK (2016, methodology): “More recently, Nakanishi & Sofue (2006), Pohl et al. (2008) and Rice et al. (2016) exploited the full coverage of the Galactic plane of the Dame et al. (2001) 12CO atlas.”
• Molecular Clouds in the Milky Way (2015, methodology): “…6 8 10 12 14 16 18 Axisymmetric (Bronfman et al. 1988) Axisymmetric (Sanders et al. 1984) Double Gaussian (Clemens et al. 1988) Double Gaussian (Nakanishi & Sofue 2006) Terminal Velocity (Malhotra 1994b) Outer L=65°–116° (Digel 1991) Outer L=280°–335° (Grabelsky et al. 1987) CO near HII…”
• A NEW ELECTRON-DENSITY MODEL FOR ESTIMATION OF PULSAR AND FRB DISTANCES (2016, methodology): “Studies of the distribution of massive stars, molecular gas, and H II regions in the inner Galaxy (e.g., Nakanishi & Sofue 2006; Urquhart et al. 2014; Anderson et al. 2015) show that the gas density peaks at a Galactocentric radius of 4–5 kpc. Analyses of the z-distribution of tracers of…”
• Gas flow models in the Milky Way embedded bars (2008, methodology): “In their face-on deprojection of the neutral and molecular gas distribution, Nakanishi & Sofue (2006) found that the GMR seems to be the inner part of the Sgr-Carina arm (the far-side of the GMR) and the ScutumCrux arm (the near-side of the GMR).”