NGC 6193 is an open cluster embedded in an HII region (RCW 108, Rodgers et al. 1960) located 15^´ eastwards of NGC 6188. The later is a bright rimmed cloud that stretches over 30^´ in the north-south direction, and marks the interface between RCW 108 and nearby dark clouds. RCW 108 is being powered by the multiple O-type star systems, namely HD 150135-HD 150136 (Niemela & Gamen 2005) in the core of NGC 6193. The UV photons emitted by these stars may drive photoinization-induced shocks into the nearby molecular clouds, possibly originating the well studied infrared cluster RCW 108-IR (Comerón et al. 2005, and references therein). In this work we describe the morphology of the distribution of the photoionized and shock-excited gas based on Hα, [O III] and [S II] images, ^{13}CO observations, and infrared data (2MASS, MSX).Fil: Romero, Gisela Andrea. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomia; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Barba, Rodolfo Hector. Universidad de la Serena; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Arnal, Edmundo Marcelo. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomia; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentin

Arnal, Edmundo Marcelo

Barba, Rodolfo Hector

Romero, Gisela Andrea

Revista Mexicana de Astronomía y Astrofísica

CONICET Digital

© 2008: Instituto de Astronomía, UNAM - Massive Stars: Fundamental Parameters and Circumstellar InteractionsEd. Paula Benaglia, Guillermo Bosch, & Cristina CappaRevMexAA (Serie de Conferencias), 33, 166–166 (2008)MULTIWAVELENGTH STUDY OF RCW108 AS A MASSIVE STARFORMING REGIONG. A. Romero,1,2 R. H. Barba´,3 and E. M. Arnal1,2NGC 6193 is an open cluster embedded in anHii region (RCW 108, Rodgers et al. 1960)located 15′eastwards of NGC 6188. Thelater is a bright rimmed cloud that stretchesover 30′in the north-south direction, andmarks the interface between RCW 108 andnearby dark clouds. RCW 108 is being pow-ered by the multiple O-type star systems,namely HD 150135-HD 150136 (Niemela &Gamen 2005) in the core of NGC 6193.The UV photons emitted by these stars maydrive photoinization-induced shocks into thenearby molecular clouds, possibly originatingthe well studied infrared cluster RCW108-IR (Comero´n et al. 2005, and referencestherein). In this work we describe the mor-phology of the distribution of the photoion-ized and shock-excited gas based on Hα, [OIII] and [S II] images, 13CO observations, andinfrared data (2MASS, MSX).The spatial distribution of dust (Band A fromMSX satellite, HPBW:18′′) and molecular gas(13CO(1-0), HPBW:2.′7) are shown in Figure 1. Noinfrared emission is detected between NGC 6193 andNGC 6188, suggesting that the cluster has swept thedust. In this region the maximum [OIII]/Hα line ra-tio (0.24 ± 0.05) is observed.There are knots of warm dust along the imagewhich are related to molecular gas associated withRCW 108. This gas shows 13CO emission with radialvelocities in the range [−30,−20] km s−1 (Romero2006). These structures depict the highest values[S II]/Hα (0.22 ± 0.04) over the entire surveyedarea. This high [S II]/Hα line ratio usually pin-points to interface between molecular and ionizedgas, the so-called photodissociation regions (PDRs).In this way four PDRs have been identified in thisregion: one with a blister morphology seen to thenortheast of NGC 6188 (A), a semi-annular structure1Instituto Argentino de Radioastronomı´a, Casilla deCorreo No 5, 1894 Villa Elisa, Provincia de Buenos Aires,Argentina (gisela@iar.unlp.edu.ar).2Facultad de Ciencias Astrono´micas y Geof´ısicas, Paseodel Bosque S/N, B1900FWA La Plata, Provincia de BuenosAires, Argentina.3Universidad de La Serena, La Serena, Chile.Fig. 1. Overlay of the MSX A-band emission (8 µm,grey-scale image) and the 13CO emission (contour lines)associated with RCW 108. The objects referred to in thetext are marked in this figure.southwards of NGC 6193 (B), other associated withboth NGC 6188 and RCW 108-IR (see Comero´n etal. 2005), and finally, one situated westwards toNGC 6188 where the dark cloud Sandqvist 182 ispresent (D). Based on the analysis of near infraredcolour diagrams using data retrieved from 2MASSand MSX point sources catalogues, all of the PDRsare associated with sources candidates to be youngstellar objects. For the case of Structure D, a youngstellar cluster may be embedded in the molecularcloud.These results indicate that the star-forming pro-cess in the region of RCW 108 is a much morewidespread phenomenon that previously thought.REFERENCESComero´n, F., Schneider, N., & Russeil, D. 2005, A&A,433, 955Niemela, V. S., & Gamen, R. C. 2005, MNRAS, 356, 974Rodgers, A. W., Campbell, C. T., & Whiteoak, J. B.1960, MNRAS, 121, 103Romero, G. A. 2006, PhD Thesis, Argentina166

Multiwavelength study of RCW 108 as a massive star forming region

LAReferencia - Red Federada de Repositorios Institucionales de Publicaciones Científicas Latinoamericanas

© 2008: Instituto de Astronomía, UNAM - Massive Stars: Fundamental Parameters and Circumstellar InteractionsEd. Paula Benaglia, Guillermo Bosch, & Cristina CappaRevMexAA (Serie de Conferencias), 33, 166–166 (2008)MULTIWAVELENGTH STUDY OF RCW108 AS A MASSIVE STARFORMING REGIONG. A. Romero,1,2 R. H. Barbá,3 and E. M. Arnal1,2NGC 6193 is an open cluster embedded in anHii region (RCW 108, Rodgers et al. 1960)located 15′eastwards of NGC 6188. Thelater is a bright rimmed cloud that stretchesover 30′in the north-south direction, andmarks the interface between RCW 108 andnearby dark clouds. RCW 108 is being pow-ered by the multiple O-type star systems,namely HD 150135-HD 150136 (Niemela &Gamen 2005) in the core of NGC 6193.The UV photons emitted by these stars maydrive photoinization-induced shocks into thenearby molecular clouds, possibly originatingthe well studied infrared cluster RCW108-IR (Comerón et al. 2005, and referencestherein). In this work we describe the mor-phology of the distribution of the photoion-ized and shock-excited gas based on Hα, [OIII] and [S II] images, 13CO observations, andinfrared data (2MASS, MSX).The spatial distribution of dust (Band A fromMSX satellite, HPBW:18′′) and molecular gas(13CO(1-0), HPBW:2.′7) are shown in Figure 1. Noinfrared emission is detected between NGC 6193 andNGC 6188, suggesting that the cluster has swept thedust. In this region the maximum [OIII]/Hα line ra-tio (0.24 ± 0.05) is observed.There are knots of warm dust along the imagewhich are related to molecular gas associated withRCW 108. This gas shows 13CO emission with radialvelocities in the range [−30,−20] km s−1 (Romero2006). These structures depict the highest values[S II]/Hα (0.22 ± 0.04) over the entire surveyedarea. This high [S II]/Hα line ratio usually pin-points to interface between molecular and ionizedgas, the so-called photodissociation regions (PDRs).In this way four PDRs have been identified in thisregion: one with a blister morphology seen to thenortheast of NGC 6188 (A), a semi-annular structure1Instituto Argentino de Radioastronomı́a, Casilla deCorreo No 5, 1894 Villa Elisa, Provincia de Buenos Aires,Argentina (gisela@iar.unlp.edu.ar).2Facultad de Ciencias Astronómicas y Geof́ısicas, Paseodel Bosque S/N, B1900FWA La Plata, Provincia de BuenosAires, Argentina.3Universidad de La Serena, La Serena, Chile.Fig. 1. Overlay of the MSX A-band emission (8 µm,grey-scale image) and the 13CO emission (contour lines)associated with RCW 108. The objects referred to in thetext are marked in this figure.southwards of NGC 6193 (B), other associated withboth NGC 6188 and RCW 108-IR (see Comerón etal. 2005), and finally, one situated westwards toNGC 6188 where the dark cloud Sandqvist 182 ispresent (D). Based on the analysis of near infraredcolour diagrams using data retrieved from 2MASSand MSX point sources catalogues, all of the PDRsare associated with sources candidates to be youngstellar objects. For the case of Structure D, a youngstellar cluster may be embedded in the molecularcloud.These results indicate that the star-forming pro-cess in the region of RCW 108 is a much morewidespread phenomenon that previously thought.REFERENCESComerón, F., Schneider, N., & Russeil, D. 2005, A&A,433, 955Niemela, V. S., & Gamen, R. C. 2005, MNRAS, 356, 974Rodgers, A. W., Campbell, C. T., & Whiteoak, J. B.1960, MNRAS, 121, 103Romero, G. A. 2006, PhD Thesis, Argentina166

English

NGC 6193 is an open cluster embedded in an Hii region (RCW 108, Rodgers et al. 1960) located 15 0 eastwards of NGC 6188. The later is a bright rimmed cloud that stretches over 30 0 in the north-south direction, and marks the interface between RCW 108 and nearby dark clouds. RCW 108 is being powered by the multiple O-type star systems, namely HD 150135-HD 150136 (Niemela & Gamen 2005) in the core of NGC 6193.
The UV photons emitted by these stars may drive photoinization-induced shocks into the nearby molecular clouds, possibly originating the well studied infrared cluster RCW108- IR (Comerón et al. 2005, and references therein). In this work we describe the morphology of the distribution of the photoionized and shock-excited gas based on Hα, [O III] and [S II] images, 13CO observations, and infrared data (2MASS, MSX).Facultad de Ciencias Astronómicas y Geofísica

Barbá, Rodolfo Héctor

El Servicio de Difusión de la Creación Intelectual

©
 2
00
8:
 In
st
itu
to
 d
e
 A
st
ro
no
m
ía
, U
N
A
M
 -
 M
a
ss
iv
e
 S
ta
rs
: F
un
d
a
m
e
nt
a
l P
a
ra
m
e
te
rs
 a
nd
 C
irc
um
st
e
lla
r I
nt
e
ra
c
tio
ns
Ed
. P
a
ul
a
 B
e
na
g
lia
, G
ui
lle
rm
o
 B
o
sc
h,
 &
 C
ris
tin
a
 C
a
p
p
a
RevMexAA (Serie de Conferencias), 33, 166–166 (2008)
MULTIWAVELENGTH STUDY OF RCW108 AS A MASSIVE STAR
FORMING REGION
G. A. Romero,1,2 R. H. Barba´,3 and E. M. Arnal1,2
NGC 6193 is an open cluster embedded in an
Hii region (RCW 108, Rodgers et al. 1960)
located 15
′
eastwards of NGC 6188. The
later is a bright rimmed cloud that stretches
over 30
′
in the north-south direction, and
marks the interface between RCW 108 and
nearby dark clouds. RCW 108 is being pow-
ered by the multiple O-type star systems,
namely HD 150135-HD 150136 (Niemela &
Gamen 2005) in the core of NGC 6193.
The UV photons emitted by these stars may
drive photoinization-induced shocks into the
nearby molecular clouds, possibly originating
the well studied infrared cluster RCW108-
IR (Comero´n et al. 2005, and references
therein). In this work we describe the mor-
phology of the distribution of the photoion-
ized and shock-excited gas based on Hα, [O
III] and [S II] images, 13CO observations, and
infrared data (2MASS, MSX).
The spatial distribution of dust (Band A from
MSX satellite, HPBW:18
′′
) and molecular gas
(13CO(1-0), HPBW:2.′7) are shown in Figure 1. No
infrared emission is detected between NGC 6193 and
NGC 6188, suggesting that the cluster has swept the
dust. In this region the maximum [OIII]/Hα line ra-
tio (0.24 ± 0.05) is observed.
There are knots of warm dust along the image
which are related to molecular gas associated with
RCW 108. This gas shows 13CO emission with radial
velocities in the range [−30,−20] km s−1 (Romero
2006). These structures depict the highest values
[S II]/Hα (0.22 ± 0.04) over the entire surveyed
area. This high [S II]/Hα line ratio usually pin-
points to interface between molecular and ionized
gas, the so-called photodissociation regions (PDRs).
In this way four PDRs have been identified in this
region: one with a blister morphology seen to the
northeast of NGC 6188 (A), a semi-annular structure
1Instituto Argentino de Radioastronomı´a, Casilla de
Correo No 5, 1894 Villa Elisa, Provincia de Buenos Aires,
Argentina (gisela@iar.unlp.edu.ar).
2Facultad de Ciencias Astrono´micas y Geof´ısicas, Paseo
del Bosque S/N, B1900FWA La Plata, Provincia de Buenos
Aires, Argentina.
3Universidad de La Serena, La Serena, Chile.
Fig. 1. Overlay of the MSX A-band emission (8 µm,
grey-scale image) and the 13CO emission (contour lines)
associated with RCW 108. The objects referred to in the
text are marked in this figure.
southwards of NGC 6193 (B), other associated with
both NGC 6188 and RCW 108-IR (see Comero´n et
al. 2005), and finally, one situated westwards to
NGC 6188 where the dark cloud Sandqvist 182 is
present (D). Based on the analysis of near infrared
colour diagrams using data retrieved from 2MASS
and MSX point sources catalogues, all of the PDRs
are associated with sources candidates to be young
stellar objects. For the case of Structure D, a young
stellar cluster may be embedded in the molecular
cloud.
These results indicate that the star-forming pro-
cess in the region of RCW 108 is a much more
widespread phenomenon that previously thought.
REFERENCES
Comero´n, F., Schneider, N., & Russeil, D. 2005, A&A,
433, 955
Niemela, V. S., & Gamen, R. C. 2005, MNRAS, 356, 974
Rodgers, A. W., Campbell, C. T., & Whiteoak, J. B.
1960, MNRAS, 121, 103
Romero, G. A. 2006, PhD Thesis, Argentina
166


http://sedici.unlp.edu.ar/bitstream/handle/10915/99614/11336_22325_1_CONICET_Digital_Nro.20668.pdf-PDFA.pdf.pdf?sequence=1

Multiwavelength study of RCW 108 as a massive star forming region

Abstract

Similar works

Full text

Available Versions

CONICET Digital

LAReferencia - Red Federada de Repositorios Institucionales de Publicaciones Científicas Latinoamericanas

El Servicio de Difusión de la Creación Intelectual