Free Access

Table 1

Geometrical parameters of the different structural components in our representation of the interstellar gas.

Component Shape Dimensions [pc]a Volume [pc3] Position [pc]b

Central cavity (CC) ellipsoid lx × ly × lz = 2.9 × 2.9 × 2.1 9.2 centered on Sgr A
 Extended component 8.4
 Minispiral l = 9.7 and d = 0.1 0.076
 Neutral streamers l = 6.2 and d = 0.3 0.44
 Central sphere d = 0.8 0.27

Circumnuclear ring (CNR) trapezoidal ring rin = 1.2, rout = 3.0 and hin = 0.4, hout = 1.0 18 centered on Sgr A
 Main molecular ring rin = 1.2, rout = 3.0 18
 Photo-dissociated inner layer rin = 1.2, rout,a = 1.6 1.65

Sgr A East SNR ellipsoid Lx × Ly × Lz = 9.0 × 9.0 × 6.7 285 (xc,yc,zc) = (−2.0,1.2, −1.5)
 Extended component 260

Radio halo sphere d = 18 3 050 (xc,yc,zc) = (−2.0,1.2, −1.5)
 Extended component 2 440

Belt of molecular cloudsc,d
 M−0.13−0.08 (SC) ellipsoid x × y × z = 7.5 × 15 × 7.5 442 (xSC,ySC,zSC) = (4 − 12, − 11, − 5)
 M−0.02−0.07 (EC) indented sphere d = 9 356 (xEC,yEC,zEC) = ( − 3,7, − 4.5)
  Preshock core 305
  Swept-up shell Δr = 1.5 51 along NE bdy of SNR
 Molecular ridge (MR) 79–98
  Swept-up shell Δr = 1.5 51 along NE bdy of SNR
  Bridge curved cylinder l = (9−15) and d = 2 28–47 between EC and SC
 Southern streamer (SS) curved cylinder l = (7−14) and d = 2 22–44 between SC and CNR
 Western streamer (WS) curved cylinder l = 8 and d = 1 6 along W bdy of SNR
 Northern ridge (NR) curved cylinder l = 4 and d = 1 3 along N bdy of SNR

Notes. 

(a)

The errors in our adopted dimensions, which arise from observational uncertainties and from our geometrical approximations, are estimated as follows [in pc]: central cavity: δly ≈ δlz ≈ 0.5. Minispiral: δl ≈ 4, . Neutral streamers: δl ≈ 3, δd ≈ 0.15. Central sphere: δd ≈ 0.4. CNR: δrin ≈ 0.4, , δhin ≈ 0.2, δhout ≈ 0.5. Sgr A East: δLy ≈ δLz ≈ 1.5. Radio halo: δd ≈ 5. M − 0.13 − 0.08: δy ≈ δz ≈ 3. M − 0.02 − 0.07: δd ≈ 3. Swept-up shell: δΔr ≈ 0.7. Bridge and southern streamer: δd ≈ 1. Western streamer and northern ridge: δl ≈ 2, δd ≈ 0.5.

(b)

The errors in our adopted positions are estimated as follows [in pc]:  ≈ 0.1 for the central cavity;  ≈ 0.3 for the CNR and Sgr A East;  ~ 2 for the radio halo and the different molecular clouds in the belt.

(c)

The swept-up shell is indicated twice, because it is part of both M − 0.02 − 0.07 and the molecular ridge.

(d)

The ranges given for the lengths and volumes of the Bridge (and hence the molecular ridge) and the southern streamer correspond to the range in the line-of-sight coordinate of the center of M − 0.13 − 0.08, xSC.

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.