J/ApJ/866/87 VLA 22GHz water masers obs. in NGC6334I-MM1 (Brogan+, 2018)
The extraordinary outburst in the massive protostellar system NGC 6334I-MM1:
flaring of the water masers in a north-south bipolar outflow driven by MM1B.
Brogan C.L., Hunter T.R., Cyganowski C.J., Chibueze J.O., Friesen R.K.,
Hirota T., MacLeod G.C., McGuire B.A., Sobolev A.M.
<Astrophys. J., 866, 87-87 (2018)>
=2018ApJ...866...87B 2018ApJ...866...87B (SIMBAD/NED BibCode)
ADC_Keywords: Masers; Radio continuum
Keywords: ISM: individual objects: NGC 6334I; masers; radio continuum: ISM;
stars: formation; stars: protostars; submillimeter: ISM
Abstract:
We compare multi-epoch sub-arcsecond Very Large Array imaging of the
22GHz water masers toward the massive protocluster NGC 6334I observed
before and after the recent outburst of MM1B in (sub)millimeter
continuum. Since the outburst, the water maser emission toward MM1 has
substantially weakened. Simultaneously, the strong water masers
associated with the synchrotron continuum point source CM2 have flared
by a mean factor of 6.5 (to 4.2kJy) with highly blueshifted features
(up to 70km/s from the LSR) becoming more prominent. The strongest
flaring water masers reside 3000au north of MM1B and form a remarkable
bow shock pattern whose vertex coincides with CM2 and tail points back
to MM1B. Excited OH masers trace a secondary bow shock located ∼120au
downstream. Atacama Large Millimeter Array images of CS (6-5) reveal a
highly collimated north-south structure encompassing the flaring
masers to the north and the nonflaring masers to the south seen in
projection toward the MM3-UCHII region. Proper motions of the southern
water masers over 5.3 years indicate a bulk projected motion of
117km/s southward from MM1B with a dynamical time of 170 years. We
conclude that CM2, the water masers, and many of the excited OH masers
trace the interaction of the high-velocity bipolar outflow from MM1B
with ambient molecular gas. The previously excavated outflow cavity
has apparently allowed the radiative energy of the current outburst to
propagate freely until terminating at the northern bow shock where it
strengthened the masers. Additionally, water masers have been detected
toward MM7 for the first time, and a highly collimated CS (6-5)
outflow has been detected toward MM4.
Description:
The VLA 22.235GHz water maser spectral line data presented in this
paper arise from three epochs: 2011.7, 2017.0, and 2017.8. The 2011.7
epoch data were also presented in Brogan+ (2016, J/ApJ/832/187).
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
17 20 53.35 -35 47 01.5 NGC 6334-I = NAME NGC 6334-I
17 20 53.42 -35 46 57.8 MM1B = [BHC2016] MM1B
----------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 64 602 Fitted properties of the 22GHz water masers
in the epoch 2011.7 data (2011 Sep 09)
table3.dat 65 880 Fitted properties of the 22GHz water masers
in the epoch 2017.0 data (2017 Jan 08)
table4.dat 65 1217 Fitted properties of the 22GHz water masers
in the epoch 2017.8 data (2017 Oct 08)
table5.dat 102 19 Brightness summary of 22GHz water
maser associations
table6.dat 72 19 Velocity summary of 22GHz water maser associations
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See also:
II/316 : UKIDSS-DR6 Galactic Plane Survey (Lucas+ 2012)
J/A+A/316/102 : JHK Photometry in NGC 6334 (Tapia+, 1996)
J/A+AS/137/43 : OH/H2O masers database (Forster+, 1999)
J/A+A/432/369 : Leiden Atomic and Molecular Database (LAMDA) (Schoeier+, 2005)
J/A+A/451/1125 : Rotational excitation of CS (Lique+, 2006)
J/A+A/481/169 : ATCA 3mm obs. of NGC 6334I and NGC 6334I(N) (Beuther+, 2008)
J/ApJ/707/1 : Water and Methanol masers in NGC 6334I(N) (Brogan+, 2009)
J/ApJ/783/130 : Parallaxes of high mass star forming regions (Reid+, 2014)
J/ApJ/832/187 : ALMA and VLA radio continuum obs. of NGC 6334I (Brogan+, 2016)
J/ApJ/851/L46 : CH3OCH2OH ALMA detection in NGC 6334I (McGuire+, 2017)
J/ApJ/854/170 : Methanol (CH3OH) and OH masers in NGC 6334I (Hunter+, 2018)
Byte-by-byte Description of file: table[234].dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- Seq Running sequence number
6- 13 A8 --- Assoc Association identifier
15- 20 F6.2 km/s VelCh [-78/14] Velocity channel
22- 23 I2 h RAh [17] Hour of Right Ascension (J2000)
25- 26 I2 min RAm [20] Minute of Right Ascension (J2000)
28- 34 F7.4 s RAs [53/60] Second of Right Ascension (J2000)
36 A1 --- DE- [-] Sign of the Declination (J2000)
37- 38 I2 deg DEd [35] Degree of Declination (J2000)
40- 41 I2 arcmin DEm [46/47] Arcminute of Declination (J2000)
43- 48 F6.3 arcsec DEs Arcsecond Declination (J2000)
50- 58 F9.4 Jy Flux [-145/4230] Fitted flux density in VelCh
60- 65 F6.4 Jy e_Flux [0.003/1.3] Uncertainty in Flux (1)
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Note (1): Does not include the flux calibration uncertainty of 10%.
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Assoc Association or total
13- 14 I2 h RAh ? Hour of right ascension (J2000)
16- 17 I2 min RAm ? Minute of right ascension (J2000)
19- 24 F6.3 s RAs ? Second of right ascension (J2000)
26 A1 --- DE- Sign of declination (J2000)
27- 28 I2 deg DEd ? Degree of declination (J2000)
30- 31 I2 arcmin DEm ? Arcminute of declination (J2000)
33- 37 F5.2 arcsec DEs ? Arcsecond of declination (J2000)
39- 45 F7.2 Jy.km/s Flux1 [4.7/2880]? Integrated flux in the epoch 2011.7
47- 54 F8.2 Jy.km/s Flux2 [1.2/12500]? Integrated flux in the epoch 2017.0
56- 64 F9.3 Jy.km/s Flux3 [0.2/12600]? Integrated flux in the epoch
in the epoch 2017.8
66- 70 F5.3 --- R2/1 ? Integrated flux 2017.0 to 2011.7 ratio
71 A1 --- f_R2/1 Flag on R2/1 (n=new; v=vanished)
73- 77 F5.3 --- R3/1 ? Integrated flux 2017.8 to 2011.7 ratio
78 A1 --- f_R3/1 Flag on R3/1 (n=new; v=vanished)
80- 85 F6.2 Jy hFlux1 [2/398]? Highest flux density
in the epoch 2011.7
87- 93 F7.2 Jy hFlux2 [1/3920]? Highest flux density
in the epoch 2017.0
95-102 F8.3 Jy hFlux3 [0.2/4230]? Highest flux density
in the epoch 2017.8
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Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Assoc Association or total
13- 18 F6.2 km/s Vlsrmin1 [-64.5/-8.2]? Minimum LSR velocity in
the epoch 2011.7
20- 25 F6.2 km/s Vlsrmin2 [-24.3/8.8]? Minimum LSR velocity in
the epoch 2017.0
27- 31 F5.2 km/s Vlsrmin3 [-8/9.8]? Minimum LSR velocity in
the epoch 2017.8
33- 38 F6.2 km/s VlsrPk1 [-62/2.8]? Peak LSR velocity in
the epoch 2011.7
40- 45 F6.2 km/s VlsrPk2 [-59/4]? Peak LSR velocity in the epoch 2017.0
47- 51 F5.2 km/s VlsrPk3 [-9/9]? Peak LSR velocity in the epoch 2017.8
53- 58 F6.2 km/s Vlsrmax1 [-78/3.3]? Maximum LSR velocity in
the epoch 2011.7
60- 65 F6.2 km/s Vlsrmax2 [-60.8/8.3]? Maximum LSR velocity in
the epoch 2017.0
67- 72 F6.2 km/s Vlsrmax3 [-59.8/14]? Maximum LSR velocity in
the epoch 2017.8
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 04-Oct-2019