Plunkett Status: T Aﬃl.: Yale University Astronomy, P.O

Yale Observing Proposal Standard proposal Semester: 2014B Date: March 10, 2014

Kinematics and Excitation of Jets in Star Forming Re- gions: The ﬁnal epoch

PI: Adele Plunkett Status: T Aﬃl.: Yale University Astronomy, P.O. Box 208101, New Haven, CT 06520-8101 U.S.A. Email: [email protected] Phone: FAX: 203-432-5119

CoI: Hector G. Arce Status: P Aﬃl.: Yale University

Abstract of Scientiﬁc Justiﬁcation (will be made publicly available for accepted proposals):

This is the final epoch for WIYN/WHIRC images of infrared jets from protostars in the young Perseus cluster NGC 1333. H2 (2.12 µm) observations of jet shocks are complementary to previous mm-wavelength observations of outflows in this region, and we will measure proper motions of shocks as low as 20 km sec−1. In addition, we will observe [FeII] (1.65 µm) to determine the [FeII]/H2 ratio and study the excitation variation along jets at each epoch of observations. With a 6 year baseline, we will be able to derive for the first time the proper motions, shock excitation and velocity structure of a sample of jets at different ages and source luminosities. In combina- tion with other existing observations, these observations will provide a crucial component for an unprecedented multi-wavelength study of outflows and their impact on their natal cloud.

Summary of observing runs requested for this project Run Telescope Instrument No. Nights Min. Nights Moon Optimal months Accept. months 1 WIYN WHIRC 4 bright November October to December 2 3 4 5

Scheduling constraints and non-usable dates (up to four lines). —————————————————— Yale Proposal Page 2 This box blank.

Scientific Justification Be sure to include overall significance to astronomy. Limit text to one page with figures, captions and references on no more than two additional pages. As stars form, infall and accretion are balanced by simultaneous bipolar flows of ejected material. Acting as vital feedback components of the star formation process, the energetic jets and outflows from young stars inject energy and momentum into their surrounding cloud, modify the density structure of the cloud, trigger certain chemical reactions, and perhaps drive turbulence in the gas (e.g. Arce et al. 2007). The interaction between jets and their natal molecular clouds is important for understanding star formation and molecular cloud evolution. Given that most stars form in groups or clusters embedded within molecular clouds (Lada & Lada 2003), dense gaseous regions surrounding multiple embedded protostars are the best environments to study protostellar feedback.

Infrared (IR) H2 knots, Herbig-Haro (HH) objects, and molecular outflows are evidence of a nascent star’s mass loss and subsequent impact on the surrounding cloud. Since these features emit wave- lengths ranging from optical to radio, the most holistic method to understand these distinct yet complementary components is a multi-wavelength study of a very active region such as NGC 1333, the prototypical star-forming cluster (see Figure 1). H2 emission traces shocked molecular gas (with typical shock velocities of tens to hundreds km sec−1) that is associated with the entrained gas of molecular outflows (Bachiller 1996). In some cases, the H2 is more apparent than the molecular outflows in deeply embedded clouds and reveals vital information of star formation in that region. Additionally, an intricate web of mm-wavelength emission from molecular outflows can be disentangled using proper motions of H2 features. Plunkett et al. (2013) present mm-wavelength observations of the molecular outflows in NGC 1333, identify outflows and outflow candidates, and measure masses and kinematics of outflowing gas in the region. However, there remain several ambiguities in the molecular outflow emission maps that will be clarified with the proposed IR observations, allowing us to better characterize this region of active star formation. In particular, IR observations of NGC 1333 over several epochs will allow us to determine the proper motions of the H2 knots and identify the driving sources of jets and outflows. Whereas mm-wavelength molecular outflow observations only give spectral information, and there- fore radial velocities, the multi-epoch IR H2 observations provide spatial information on the plane of the sky. In November 2008 and 2011 we obtained the first two epochs of observations of IR jets in NGC 1333, with the expectation of obtaining one more epoch in this campaign. With a three-year baseline (using datasets from 2008 and 2011), we measured proper motions greater than about 40 km sec−1 (see Figure 2). Extending the temporal baseline to six years and perfecting our analysis method, we will be able to measure proper motions as low as about 20 km sec−1, in order to identify and characterize jets with lower energy, as well as jets that happen to be oriented nearly along the line of sight (with small transverse velocity).

In addition to measuring H2 knot proper motions, we will observe [FeII] (1.65 µm) in the same region. While H2 traces weaker (low-excitation) molecular gas in non-dissociative shocks, [FeII] emission in jets arises from hot, dense partially ionized gas (T ∼ 10,000 K) in fast dissociative shocks (Reipurth et al. 2000; Davis et al. 2006). The [FeII]/H2 ratio reveals excitation variation along the jet, and we will study the changes of excitation structure during the six years 2008-2014. References Arce, H. G., et al. 2007, in PPV, 245 • Bachiller, R. 1996, ARA&A, 34, 111 • Chrysostomou, A., et al. 2000, MNRAS, 314, 229• Davis, C. J., et al. 1999, MNRAS, 308, 539• Davis, C. J., et al. 2006 ApJ, 639, 969• Gutermuth et al. 2008, ApJ, 674, 336 • Lada, C. J., & Lada, E. A. 2003, ARA&A, 41, 57• McCaughrean, et al. 1994, ApJ, 436, L189• Plunkett, A. L., Arce, H. G., Corder, S. A., et al. 2013, ApJ, 774, 22• Raga et al., ApJ, 748, 103 • Reipurth, B., et al. 2000, AJ, 1449• Stanke, T., et al. 2002, A&A, 392, 239 Yale Proposal Page 3 This box blank.

Figure 1: Spitzer IRAC composite image of NGC1333 from Gutermuth et al. (2008). The image is about 240 × 180 in size, and within this region an intricate web of outflow activity is evident. The solid line shows the approximate 240 × 90 extent of the WHIRC mosaic observed in 2008B and 2011B, and the same region we propose to observe as the final epoch for a 6-year baseline. In 2013B we lost most of the allocated time due to weather, but we observed a small region in H2-only in preparation for the final epoch in 2014B. Yale Proposal Page 4 This box blank.

Figure 2: H2 sample field in NGC 1333 observed with WIYN in 2008 (upper) and 2011 (lower). Panels are approximately 10 ×1.80, shown here to highlight one particular region of shocked emission and corresponding to approximately one third of a WHIRC field of view. A reference star (yellow, at least four such reference stars are used to align fields across epochs) and several shock features are marked. Features marked with blue have structures such that the ‘imexam’ task in ds9 sufficiently fits a radial profile and determines a central coordinate, and blue vectors show trajectories of these features from 2008 to 2013. For these features, we used preliminary 2013 observations to measure proper motions as a proof of concept in this particular field, with results between ∼ 30 and 100 km s−1. Unfortunately, due to lost telescope time in 2013, we were not able to complete observations for the majority of the proposed fields, and the current proposal seeks to do so in 2014. Features marked with green are more diffuse structures for which we are developing an improved cross-correlation method for measuring proper motions. Yale Proposal Page 5 This box blank.

Impact to Yale Astronomy Describe how this program fits into the Yale astronomy program. Will the data analysis and resulting papers be based at Yale? If the project is led by a faculty member, does the project involve students? What is the role of the PI viz-a-viz other non-Yale co-Is. Are the resources in place to analyze the data and come to a timely publication? (limit text to one page) This is a continuation of a multi-wavelength (from IR to millimeter) observing campaign of star- forming regions initiated by Prof. H. Arce and now led by PhD student A. Plunkett. The IR observations from WIYN are an important component of the PhD thesis. The goal of the thesis by A. Plunkett is to investigate the impact of outflows in molecular clouds at different evolutionary stages, and her sample of molecular clouds includes NGC 1333 as the prototype, as well as various observations of Serpens South, M8 and Circinus. The focus of our IR observations since 2008 has been the NGC1333 cluster, a very active region of star-formation that harbors outflows powered by protostars at different evolutionary stages (Gutermuth et al. 2008). Other observations relevant to the study are:

• CARMA maps of NGC 1333, including a 126-point mosaic of the 60 × 60 dense central region (Plunkett et al. 2013) and a 168-point mosaic of the 60 × 80 region toward the northern extent of the cluster. 12CO (115.27 GHz), 13CO (110.20 GHz), C18O (109.78 GHz) J=1-0 transitions probe the outﬂows and the cloud structure.

• FCRAO 14m observations of the same CO isotopologues in NGC 1333. CARMA and FCRAO maps were combined by Plunkett et al. (2013) to increase sensitivity to small- as well as large- scale structures (ranging from 1000 AU to 0.5 pc at a distance 235 pc).

• Herschel Space Observatory [O I] 63 µm and H2O observations in these regions; Herschel analysis will rely on knowing shock velocities of the shocks for studying the jet-cloud momentum transfer.

• NGC 1333 was observed using WHIRC in 2008 and 2011, with the expectation of one more epoch to achieve a temporal baseline of 6 years. Preliminary proper motion analysis has commenced (see Figure 2) using the previous epochs of data, as well as what could be gathered from an incomplete 2013 observing run (see “Previous Use” section for more details). The ﬁnal epoch in 2014 will yield a full and consistent mapping to meet our science goals. Yale Proposal Page 6 This box blank.

Previous Use of Yale Facilities and Publications Please list previous use of Yale observing facilities and any publications resulting from these data in the past 3 years. If this is a long term project, please state this here and describe the overall strategy of the project. NGC 1333 was observed using WHIRC in 2008B and 2011B, and preliminary proper motion analysis commenced with these observations. The original goal was to obtain a six-year baseline, ideally observing the final epoch in 2014 to comprise part of the thesis work of A. Plunkett (expected graduation in 2015). We previously applied to observe the third epoch doing the 2013B semester because it was thought in the Spring of 2013 that Yale would not have access to WIYN in the 2014B semester. We were granted 4 nights of observing time in November 2013, but due to adverse weather conditions, the telescope dome was opened for less than 5 hours during the entire 4 night observing run. Our 2013 run resulted in observations of 15 (of the 30 proposed) WHIRC fields using the H2 filter only. This comprises approximately 1/8 of the proposed observing project with all filters, which was undertaken during about 1/8 of the allotted time. During those sparse hours, we prioritized observations of H2 knots near the center of NGC 1333 (one such region is shown in Figure 2) in preparation for this final epoch in 2014 that became necessary (and fortunately became available due to agreements at WIYN). In addition to reduced observing time, the weather and the telescope focus during those few hours were also not ideal for our proposed science goals. With the 2008 and 2011 observations we detected proper motions greater than about 40 km sec−1, and with a six year baseline we will measure proper motions as low as about 20 km sec−1. No paper has been published because a paper with a 6-year baseline will be substantially stronger, with proper motions detected for more knots and with greater precision, and we think that including a final epoch will be more beneficial towards the thesis goals. Yale Proposal Page 7 This box blank.

Observing Run Details for Run 1: WIYN/WHIRC

Technical Description Describe the observations to be made during the requested observing run. Justify the specific telescopes, the number of nights, the instrument, and the lunar phase. List objects, coordinates, and magnitudes (or surface brightness, if appropriate) in the Target Tables section. We base our observations on the previous epoch runs in 2008 and 2011, and particularly this proposal follows the same motivation as the most recent proposal in 2013 (with 4 nights granted but nearly all observing time lost to weather). We will use the H2 (2.12 µm) and [FeII] (1.65 µm) narrow filters as well as the Ks and H wide-band filters. The narrow-band filters probe the excitation structure of the shocks, as each narrow filter probes a different excitation regime (see scientific motivation above). The H and Ks wide-band filters will be used to discriminate between the continuum and the [FeII] and H2 line emission, respectively. In the multi-epoch study to obtain precise proper motions of shocks in this region, WHIRC’s pixel scale of 0.100 pixel−1 is crucial for precise measurements. With a seeing of about 0.4 − 0.800, preliminary analysis of the previous epochs suggests that we are able to confidently detect proper motions of about 0.05 arcsec yr−1 with a baseline of 3 years (0.13 arcsec over three years, corresponding to one-third of the achieved resolution). For Perseus (at d∼235 pc) this translates to tangential velocities of 40 km sec−1 – an improvement of at least a factor of two with respect to other ground-based IR shock proper motion surveys (e.g., Chrysostomou et al. 2000). With a final epoch of data and a 6-year baseline, as well as a more precise analysis method currently being refined using the first two epochs of data (i.e., by cross-correlating frames from different epochs and fitting the cross-correlation function, as in Raga et al. 2012), we will detect tangential velocities down to 20 km sec−1, allowing us to detect relatively slow shocks. In addition, parts of the NGC1333 cluster (but not the entire cluster) have been observed in the IR by others (e.g., Chrysostomou et al. 2000). We will use these IR observations for several smaller regions obtained at other telescopes to increase our temporal baseline. Previous studies show that a sensitivity of about 10−19 W m−2 arcsec−2 is sufficient to detect nu- merous extended H2 shocks of varying intensity in an active star forming region (e.g., McCaughrean et al. 1994; Davis et al. 1999; Stanke et al. 2002). Based on our 2008 and 2011 observations, 12 minutes integration in each narrow-band filter (i.e., H2 at 2.12 µm and [FeII] at 1.65 µm ) and 2 minutes integration in each wide-band filter (H and Ks) will ensure our desired sensitivity. The total integration time will be obtained by summing a series of shorter (0.5-2 min) exposures. Following our 2008 and 2011 observations, we aim to observe the entire NGC1333 cluster with a mosaic comprising of 30 WHIRC fields (see Fig. 1). We estimate that the entire region will take about 14 hrs to observe with all four filters. During the fall, NGC1333 (δ = 31.3◦) can be observed from Kitt Peak for about 6 hours each night, with an airmass of less than 2.0. We thus request four nights which will allow us to observe all our targets, calibration stars, flats, and biases in a consistent manner (and accounts for other overheads, based on our previous experiences at KPNO). This simple project is suitable for shared-risk observations. R.A. range of principal targets (hours): 03:29:01 Dec. range of principal targets (degrees): 31:15:00

Instrument Conﬁguration Yale Proposal Page 8 This box blank.

Filters: H2, Fe[II], K, H Slit: Fiber cable: Grating/grism: Multislit: Corrector: Order: 1 λstart: Collimator: Cross disperser: λend: Atmos. disp. corr.:

Yale observing proposal LATEX macros v1.0.