Issue |
A&A
Volume 502, Number 1, July IV 2009
|
|
---|---|---|
Page(s) | 139 - 153 | |
Section | Interstellar and circumstellar matter | |
DOI | https://doi.org/10.1051/0004-6361/200911818 | |
Published online | 29 April 2009 |
Online Material
![]() |
Figure 8:
12CO spectra at the positions of the SCUBA peaks. The line centre velocity is marked with a solid vertical line. The standard linewing criteria of 15 K at
|
Open with DEXTER |
![]() |
Figure 8: continued. |
Open with DEXTER |
![]() |
Figure 8: continued. |
Open with DEXTER |
![]() |
Figure 9: 12CO spectra at the positions of Spitzer low luminosity objects. See Fig. 8 for annotations. Available in the online version only. |
Open with DEXTER |
Appendix A: Comments on individual sources and regions
A.1 Low-luminosity objects
LL060
lies in SCUBA core HRF80, southeast of L1448, and is associated with IRAS 03235+3004 (Fig. 6). The core is detected by SHARC, and HARP clearly images the ESE-WNW red-blue outflow associated with this Class I protostar. The outflow is parsec-scale, driving HH317 30'' to the southeast (Davis et al. 2008).
LL064
is associated with SCUBA source HRF75 in the southwest part of NGC1333 (Fig. 5). The core is 2' south of HRF49, and a compact SHARC-II 350
The outflow from LL064 is not the most obvious feature in this map. There is also a strong blueshifted lobe lying between the two SCUBA cores, not associated with a dust continuum peak. The blueshifted gas is coincident with a Herbig-Haro object HH744B (Walawender et al. 2005a) and an IRAC source (presumably H2), and must be the end of an outflow driven by sources to the west, in the south of NGC1333. A good candidate is LL071 (see below).
LL065 and LL068
lie far to the SW of NGC1333 (Fig. 5). LL065 is associated with a loop of submm emission with HRF71 at its NE apex and Bolo26 to the SW. The IRAC emission for LL065 consists of an arc plus a compact source, with the latter detected by SHARC-II. Although the arc may be explained as a H2 shock, the MIPS and SHARC-II emission suggest that the compact object is protostellar. LL068 (IRAS 03256+3055) lies 1' to the east of HRF75 and HRF71 and only has a faint SCUBA core (140 mJy/beam,
LL066
is on the edge of HRF55 (Fig. 5). It is not clearly associated with a SCUBA peak, Dunham et al. (2008) do not classify it as an embedded source, and it shows no SHARC-II emission at a level of 1.6 Jy/beam (3
LL071
lies in the southern part of NGC1333 (Fig. 5), to the south of SVS13 and east of IRAS 4, associated with SCUBA HRF65. The submm core lies on a partial dust shell centred to the north which Sandell & Knee (2001) suggest is created by earlier outflow activity. There is compact 350
LL075 and LL078
(HRF61 and HRF58 respectively) lie in the far north of NGC1333 (Fig. 4). Both Spitzer sources are coincident with the SCUBA cores and show strong SHARC-II emission. In LL078 the 350


LL076/077
both show redshifted and blueshifted emission, strong at the position of LL077. These low luminosity Spitzer sources lie to the north of a submm filament running southeast from IRAS 4 and including HRF72 and HRF59 (Fig. 5). Both are classified in Group 6 by (Dunham et al. 2008) as unlikely to be embedded protostars and indeed there is very little submm emission detected by SCUBA at this position, and none detected by SHARC-II (Fig. 11). The positions of LL076 and LL077 coincide with Herbig-Haro objects HH5A and B respectively, both redshifted (Cohen et al. 1991; Herbig 1974) and extending further to the southeast (Walawender et al. 2005a), and also H2 2.12
LL081
lies in the core Bolo62 in the filament to the southwest of B1. The spectra show a weak blueshifted wing which is classified as an outflow only by the low-level criteria. LL081 lies 4' to the northeast of HRF81 (IRAS 03271+3013), which clearly drives an outflow in this direction (Fig. 3). The weak blueshifted wing at the position of LL081 could be due to this outflow; certainly, nothing in the morphology in the map convinces that LL081 is driving a separate flow. However, there is a strong SHARC-II detection at this position which suggests that this is a real protostar, and the Bolocam detection cannot be due to CO contamination. A higher S/N map would help to confirm the outflow status of this source.
LL090
lies between HRF84 and HRF89 to the west of B1. The alignment strongly suggests that LL090 may drive the blueshifted flow into HRF84 but the spectrum shows only a weak blueshifted linewing. The SCUBA detection is weak but SHARC-II detects a strong peak with a north-south extension. The flatter SED (Fig. 10) suggests that LL090 is a more evolved source, likely Class I, which may explain the relative lack of CO at the source position.
LL104
is associated with IC348 SMM3 (HRF15, Fig. 2). This submm core hosts two Spitzer sources. The southern source is the low luminosity source LL104, but it is apparently the source to the north (here labelled LL104N) which is driving a small and faint molecular outflow (Tafalla et al. 2006), also seen with HARP (Figs. 2 and 9). There is no 70




LL107/108
are interlopers with no outflow. This low luminosity / VeLLO pair 107/108 lies in the horseshoe of dense dust/gas south of IC348, offset 20'' to the NE of the peak of the SCUBA source HRF16 (Fig. 2). The SHARC-II emission peak is separated from the IRAC double detection by 15'' and extends only faintly across to the Spitzer position. The CO spectra shows a slight blue wing (0.5 K at 3 km s-1 from line centre), but this is not obviously an outflow as emission at these velocities is widespread in this region in a N-S ridge bowed to the east. The sources LL107/108 are certainly associated with H2 shocks (Eislöffel et al. 2003, 3a,b,e, see Fig. 2) which may be driven by IC 348 MMS, or the same source as the Flying Ghost Nebula (Eislöffel et al. 2003; Walawender et al. 2006). These Spitzer sources appear to be HH objects rather than protostars.
A.2 NGC1333 N
![]() |
Figure A.1:
Mean intensity maps of NGC1333 N in five velocity ranges as marked. SCUBA cores are numbered and contoured in green at (1,2,4,8,16,32) |
Open with DEXTER |
The
region in the northern part of NGC1333 deserves some further comment. The nearby, young (1 Myr) cluster NGC1333 is the ongoing subject of studies focussing on its stellar content (Wilking et al. 2004; Aspin 2003), dense cores (Walsh et al. 2007; Sandell & Knee 2001; Hatchell et al. 2005), and the relationship between the two (Gutermuth et al. 2008; Jørgensen et al. 2007; Hatchell et al. 2007b; Enoch et al. 2008). In Paper III, Hatchell determined the outflow status of the SCUBA cores in the main dense cluster using the Knee & Sandell (2000) JCMT R
B map. This central region has also now been mapped with HARP and will be discussed elsewhere (Curtis et al. in prep.). Here we concentrate instead on regions of NGC1333 where the outflows have not previously been observed, to the north and south of the main cluster.
The northern part of the NGC1333 region is dominated by the two late-type B stars which power the reflection nebula which gives the region its name. The B5e star SVS3 (Lada et al. 1996; Strom et al. 1976) and, further to the north, B7V BD
(Aspin 2003) light up cavities opening northwards away from the main cluster. In terms of the SCUBA cores, SVS3 lies just north of 54 and BD
between 57 and 67. These stars strongly heat the gas in this northern region. At the position of SVS3,
reaches 50 K; at a position 30'' to the south of BD
,
70 K (Fig. 8), indicating kinetic temperatures at least this large. Thus strong CO lines in this region indicate high temperature gas, rather than large flow masses. The B stars also drive winds with their own influence on the molecular gas.
The simple red/blue integrated intensity maps in Fig. 4 do not do full justice to the velocity structure in the molecular gas, which is additionally shown as channel maps in Fig. A.1. The SCUBA cores are associated with the main molecular component at around 7.5 km s-1, from their C18O velocities (Paper I).
At low velocities of around 2 km s-1, the low column density cloud first discovered by Loren (1976) extends across the north of the map (see sources HRF61, HRF64, HRF58, HRF91 below). This is visible in CO 3-2 above 27' though in 12CO 1-0 it can be seen to extend as far south as
22' at
increasing in strength and velocity towards the north (Brunt, priv. comm.).
There is a blueshifted gas between 3 and 7 km s-1 in the west of the map forming a N-S structure over 4' in extent with a sharply defined eastern boundary. Peak line intensities are typically 15 K. This component has neither the typical linewings of an outflow nor an obvious driving source. It is possible that it is a fossil flow which has been cut off from a driving source, which could be much further south. An alternative explanation is that winds from BD + 50 459 and SVS3 have excavated a cavity in the molecular gas, and are now heating the inner edge. The morphology of the reflection nebula (Gutermuth et al. 2008) and the dust filaments both suggest that there are strong winds blowing northwards in this region. The highest-velocity redshifted components lie in the centre south of the map, 1' to the northeast of SVS3.
We discuss the outflow status of individual sources below, but because this region is so complex many of our results are necessarily inconclusive. Embedded YSO identification based on Spitzer colours is difficult because of the high probability of finding reddened background sources, and because much of the infrared is also saturated by the bright nebula, and there are several differences between Jørgensen et al. (2007) and Gutermuth et al. (2008). The recent Davis et al. (2008) UKIRT H2 survey only identifies a couple of H2 knots attributed to the HH6 driving source IRAS7 SM1 4' to the south.
HRF54, HRF56 and HRF66
This row of submillimetre peaks lies on the northern boundary of the main NGC1333 cluster and just off the (Knee & Sandell 2000) outflow map. Flows northwards from the Class 0 source SK31 (HRF47) and NGC1333 ASR114 (HRF45) to the south may extend across these sources. Looking at the map (Fig. 4) and CO spectra, there is widespread red/blue emission. The blueshifted wing of HRF66 meets the criteria, HRF54 only shows weak wings, but the spectrum for HRF56 clearly shows red and blue wings, also apparent in the maps (Fig. A.1), so this source has all the characteristics of an outflow driving source.
In Hatchell et al. (2007b) we classified HRF54 and HRF56 as Class I and HRF66 as starless. None of the three were identified as protostars by (Jørgensen et al. 2007), but with a different classification of the Spitzer data, Gutermuth et al. (2008) identify a Class I source with HRF56 and another in the filament to the southeast, as well as three without associated SCUBA emission further to the north (see their Fig. 10). The identification of HRF56 as an embedded YSO agrees with its outflow status.
HRF63, HRF67 and HRF57
These cores lie on the northeastern boundary of the reflection nebula. Heated by BD
0.1 pc away in projection, 57 and HRF67 may be hotspots rather than true dust cores. Core HRF57 shows no evidence for outflow or embedded infrared sources. The protostellar core HRF63 (Jørgensen et al. 2007; Hatchell et al. 2007b), has evidence for a redshifted flow which extends to the south (Fig. A.1). To its north SCUBA core HRF67, also classified protostellar by Jørgensen et al. (2007) and Paper II but not by Gutermuth et al. (2008), does not classify as an outflow source based on its spectrum. The integrated intensity velocity ranges of
(blueshifted) and 10.5-20.5 km s-1 (redshifted) also pick up widespread gas components at small blueshifted velocities; CO components out to 10 km are also widespread.
HRF58,HRF61,HRF64 and HRF91
Low-luminosity Spitzer sources LL075 and LL078 were discussed in Sect. A.1. The other SCUBA cores in the filaments extending north from NGC1333, sources HRF64 and HRF91, show no evidence for either embedded protostars or outflow activity.
A.3 NGC1333 S and W
The south and west of NGC1333 contain several sources which lie outside the area covered by Knee & Sandell (2000) and have been targetted by HARP, as shown in Fig. 5. This region contains many low-luminosity sources - LL064,LL065,LL066, LL068, LL071, LL076/77, and LL078 - which are discussed in Sect. A.1 along with the nearby SCUBA cores.
HRF55 and HRF60
show no evidence for outflow from the cores though there is redshifted and blueshifted gas associated with LL066/Gutermuth et al. (2008) Class I source 18, which lies 40'' to the southeast of the SCUBA peak. (Sect. A.1). Gutermuth et al. (2008) Class I sources 16, 19 and 20 also lie 20'' to the south, 3' to the southeast and 2' to the east, respectively, so there are plenty of potential driving sources for these outflows.
HRF49
shows a blueshifted wing and blueshifted gas in a NW-SE ridge. Any red counterpart is weak and confused in the map.
HRF65
is discussed with LL071 in Sect. A.1.
HRF59 and 72
are peaks in the dust filament which runs to the southeast from NGC1333 IRAS 4. The most obvious outflow features here are red and blue peaks lying between 59 and 72 and separated by 30''. Neither HRF59 or HRF72 contain driving sources (HRF72 shows no evidence for wings), nor is there another obvious source, from the location of the peaks. The redshifted emission extends to the west and may be driven by LL071 which is 4' away (HRF65). This explains the redshifted wing at the position of HRF59 (Fig. 5. The blueshifted emission, which has an associated Herbig-Haro object HH759 (Walawender et al. 2005a), is more localised and the driving source is entirely unclear. The infrared images provide few clues, except that the HH object is extended further to the southeast.
HRF69, 71, 75 and Bolo26
are all associated with a loop of continuum emission to the south of NGC1333 which also hosts LL065 and LL068. HRF71 is discussed with LL065 (Sect. A.1). HRF69 and 75 show no linewings by either criterion. There is widespread low-level blueshifted gas in the region which peaks at the position of Bolo26 and at a position between HRF69 and HRF71. The driving source is unclear but is likely to be a source further north in NGC1333. There are several H2 shocks in this area (Davis et al. 2008, Fig. 8).
HRF85
has linewings which are detected by the low-level criterion. Both the submm continuum and the redshifted CO are arc-shaped opening to the north. The morphology of the blueshifted CO is unclear. An outflow could possibly be driven by nearby Gutermuth et al. (2008) source 13. There are no obvious H2 shocks in this field (Davis et al. 2008).
A.4 IC348 region
Maps of the IC348 region are shown in Fig. 2. The well-known outflows in this region are driven by HH211 (HRF12) and IC348 SMM2 (HRF13).
HRF15
The recently-discovered outflow from IC348 SMM3 (HRF15) (Tafalla et al. 2006) is discussed in detail above (Sect. A.1 source LL104).
HRF101
With HARP, we additionally detect an outflow from the Class I source IC348 LRL 51 (HRF101) with has a compact red lobe.
HRF14,19, 25 and 90
In the extended filaments to the east, HRF14 has a Spitzer YSO (Gutermuth et al. 2008; Jørgensen et al. 2007) and shows an outflow just visible in the HARP maps but discovered with R
HRF 16,18,20,21
are the remaining cores in the HH211 horseshoe. They do not house any Spitzer sources except LL107/108 (not protostars, as discussed in Sects. 3.2 and A.1) and do not drive any outflows.
HRF24 and 26
form part of the western filament beyond IC348 SMM3 and are apparently starless.
A.5 B1 region
Per B1 and the filament to the southwest containing IRAS 03271+3013, IRAS 03282+3035 and IRAS 03292+3039 is are shown in Fig. 2. Outflows from the main B1 cluster have been discussed in detail by us (Paper III) and Walawender et al. (2005a). We originally mapped the inner parts of the IRAS 03292+3039 (HRF76), IRAS 03282+3035 (HRF88) and IRAS 03271+3013 flows with RB but return to the latter two sources with HARP.
IRAS 03282+3035 (HRF88)
is discussed in Sect. 3.4 because of its dust continuum emission.
HRF81 (IRAS 03271+3013)
has a northeast-southwest outflow (perpendicular to the direction given by (Bachiller et al. 1991)) with a clear outflow cavity in the blueshifted flow to the northeast, and a weaker red counterpart to the southwest. The linewings from this Class I source are weak and only qualify by the low-level criteria. The connection with Bolo52/LL081 to the northeast is discussed in Sect. A.1.
HRF 5,83,84
None of the scattered SCUBA cores show evidence for outflows either in the maps or their linewings. HRF84 shows a fragment of a blueshifted flow which may be driven by LL090 (see Sect. A.1).
HRF82
is identified as a YSO by Jørgensen et al. (2007) though not by Paper II. A possible outflow can be identified by the low-level criterion and as a redshifted flow extending to the north of the SCUBA core. A better signal-to-noise CO map is required to confirm this.
A.6 L1448 and the southwest region
Outflows from L1448 are shown in Fig. 6. The only new HARP map here is HRF32, as outflows from the main sources were mapped with RB (Paper III) (see also Bachiller et al. 1991,1990; Wolf-Chase et al. 2000). We also have no new maps to add to the L1455 group, but we have mapped two isolated cores: HRF80 (IRAS 03235+3004) 10' to the west of L1455, and HRF86 which lies 15' southeast of L1448.
HRF32
is classified as having an outflow by the low-level criterion but the linewings are almost certainly due to the parsec-scale flow from L1448 N/NW (HRF 27/28) (Wolf-Chase et al. 2000), and there is no Spitzer detection.
HRF86
shows no evidence for protostellar activity.
HRF80
contains an outflow driven by LL060 and is discussed in Sect. A.1.
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.