Context :

Aims : The filamentary , \sim 10 pc scale infrared dark cloud L1287 located at a \sim 929 pc parallax distance , is actively forming a dense cluster of low-mass young stellar objects ( YSOs ) at its inner \sim 0.1 pc region .
To help understand the origin of this low-mass YSO cluster , the present work aims at resolving the gas structures and kinematics with high angular resolution .

Methods : We have performed \sim 1 ^ { \prime \prime } angular resolution ( \sim 930 AU ) observations at \sim 1.3 mm wavelengths using the Submillimeter Array ( SMA ) , which simultaneously covered the dust continuum emission , and various molecular line tracers for dense gas , warm gas , shocks , and outflows .

Results : From a \sim 2 ^ { \prime \prime } resolution 1.3 mm continuum image we identified six dense cores , namely SMA1-6 .
Their gas masses are in the range of \sim 0.4 - 4 M _ { \odot } .
From a \sim 1 ^ { \prime \prime } resolution 1.3 mm continuum image , we find a high fragmentation level , with 14 compact millimeter sources within 0.1 pc : SMA3 contains at least nine internal condensations ; SMA5 and SMA6 are also resolved with two internal condensations .
Intriguingly , one condensation in SMA3 , and one condensation in SMA5 , appear associated with the known accretion outburst YSOs RNO 1C and RNO 1B .
The dense gas tracer DCN ( 3–2 ) traces well the dust continuum emission and shows a clear velocity gradient along the NW-SE direction centered at SMA3 .
There is another velocity gradient with opposite direction around the most luminous young stellar object IRAS 00338+6312 .

Conclusions : The fragmentation within 0.1 pc in L1287 is very high compared to other regions at the same spatial scales .
The incoherent motions of dense gas flows are sometimes interpreted by being influenced by ( proto ) stellar feedback ( e.g. , outflows ) , which is not yet ruled out in this particular target source .
On the other hand , the velocities ( with respect to the systemic velocity ) traced by DCN are small , and the directions of the velocity gradients traced by DCN are approximately perpendicular to those of the dominant CO outflow ( s ) .
Therefore , we alternatively hypothesize that the velocity gradients revealed by DCN trace the convergence from the \gtrsim 0.1 pc scales infalling motion towards the rotational motions around the more compact ( \sim 0.02 pc ) sources .
This global molecular gas converging flow may feed the formation of the dense low-mass YSO cluster .
Finally , we also found that IRAS 00338+6312 is the most likely powering source of the dominant CO outflow .
A compact blue-shifted outflow from RNO 1C is also identified .