tokens: a L ~10 3 L ⊙ low-mass YSO cluster (e.g. Estalella et al. 1993 ; Quanz et al. 2007 ). Four of the YSOs, namely VLA1-4, are known to be associated with thermal radio jets ( Anglada et al. 1994 ). Based on the previous, lower angular-resolution observations of C 18 O (1–0), Umemoto et al. (1999) estimated the enclosed gas mass over the ~ 0.5-pc-scale parent molecular gas structure to be ~120 M ⊙ . Contrasting to the aforementioned OB cluster-forming regions, the bolometric luminosity of L1287 is not contributed by the nuclear burning of OB stars, but instead is contributed by the accretion luminosity of the low-mass protostars, including two known FU Orionis objects 1 RNO 1B/1C( Staude Neckel 1991 ; Kenyon et al. 1993 ; McMuldroch et al. 1995 ; Quanz et al. 2007 ), and a L ~ 600 L ⊙ Class 0/I YSO IRAS 00338 + 6312 ( Anglada et al. 1994 ). Earlier observations resolved bipolar CO outflow(s) aligning in the NE-SW direction ( Snell et al. 1990 ; Yang et al. 1991 ; Fehér et al. 2017 ), although the identification of the powering source(s) remains uncertain. Table 1 SMA observations summary. In this paper, we report the ~ 1′′ (~ 930 AU)-angular-resolution observations with the Submillimeter Array (SMA) 2 , covering the inner ~0.25-pc region of L1287. By examining the resolved 1.3 mm dust continuum emission and various molecular line tracers of dense gas, warm gas, shocks, and outflows, our aim is to elucidate how the gas flows converge from parsec scales (e.g., due to gravitational collapse) down to ~ 1000 AU scales, and how they are dynamically forming the low-mass YSO cluster. We also provide a more definite identification of the powering source of the previously reported molecular outflows. The details of our observations are presented in Sect. 2 . The observational results from the dust continuum and molecular line emission are given in Sect. 3 . In Sect. 4 we present an analysis of fragmentation, dense gas kinematics, and powering sources of the previously reported CO outflows. Our conclusions are given in Sect. 5 . 2 Observations and data reduction 2.1 Submillimeter Array observations We performed five tracks of SMA observations at ~1.3 mm wavelengths towards the inner ~0.25-pc region of L1287 between August 2013 and July 2014, which are summarized in Table 1 . The pointing and phase referencing centers of the observationsare RA(J2000) = 00 h 36 m 46.65 s , Dec(J2000) = + 63°28′57.90′′. The projected baselines of these observations range from ~4 to ~ 140 k λ . The system temperature T sys for all the observations was around 150 K. The observations were obtained with the 230 GHz receiver, with 4 GHz bandwidth in each of the upper and lower sidebands. The correlator consisted of 48 chunks, each with a bandwidth of 104 MHz. The frequency was centered at 231.3 GHz at chunk 35 of the upper sideband (USB). This configured the correlator with the lower sideband (LSB) covering from 216.48 to 220.46 GHz and the USB from 228.46 to 232.43 GHz. These
ner_tags: O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O O O O O O B-CelestialObject O O O O O O O B-Wavelength O O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O B-Wavelength I-Wavelength I-Wavelength I-Wavelength B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-CelestialObject O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-CelestialObject I-CelestialObject I-CelestialObject B-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O O O B-Formula I-Formula I-Formula I-Formula I-Formula O O O B-CelestialObject I-CelestialObject I-CelestialObject I-CelestialObject O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O B-Telescope O O O O O O O O O O O O O O O O B-Telescope I-Telescope B-Telescope O O O O O O O O B-CelestialObject O O O O B-Wavelength I-Wavelength O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Telescope I-Telescope O O O O O O B-Telescope O O B-Wavelength I-Wavelength O O O O O O O B-CelestialObject O O O O O O O O O O O O O O O O O O O O O O B-CelestialRegion I-CelestialRegion I-CelestialRegion I-CelestialRegion I-CelestialRegion I-CelestialRegion I-CelestialRegion I-CelestialRegion I-CelestialRegion I-CelestialRegion I-CelestialRegion I-CelestialRegion I-CelestialRegion O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Wavelength I-Wavelength O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Wavelength I-Wavelength O O O O O O O O O O O O O O O O O O O B-Wavelength O B-Wavelength I-Wavelength O O O O B-Wavelength O B-Wavelength I-Wavelength O