We perform a joint analysis of intrinsic alignments and cosmology using tomographic weak lensing , galaxy clustering and galaxy-galaxy lensing measurements from Year 1 ( Y1 ) of the Dark Energy Survey .
We define early- and late-type subsamples , which are found to pass a series of systematics tests , including for spurious photometric redshift error and point spread function correlations .
We analyse these split data alongside the fiducial mixed Y1 sample using a range of intrinsic alignment models .
In a fiducial Nonlinear Alignment Model ( NLA ) analysis , assuming a flat \Lambda CDM cosmology , we find a significant difference in intrinsic alignment amplitude , with early-type galaxies favouring A _ { \mathrm { IA } } = 2.38 ^ { +0.32 } _ { -0.31 } and late-type galaxies consistent with no intrinsic alignments at 0.05 ^ { +0.10 } _ { -0.09 } .
The analysis is repeated using a number of extended model spaces , including a physically motivated model that includes both tidal torquing and tidal alignment mechanisms .
In multiprobe likelihood chains in which cosmology , intrinsic alignments in both galaxy samples and all other relevant systematics are varied simultaneously , we find the tidal alignment and tidal torquing parts of the intrinsic alignment signal have amplitudes A _ { 1 } = 2.66 ^ { +0.67 } _ { -0.66 } , A _ { 2 } = -2.94 ^ { +1.94 } _ { -1.83 } , respectively , for early-type galaxies and A _ { 1 } = 0.62 ^ { +0.41 } _ { -0.41 } , A _ { 2 } = -2.26 ^ { +1.30 } _ { -1.16 } for late-type galaxies .
In the full ( mixed ) Y1 sample the best constraints are A _ { 1 } = 0.70 ^ { +0.41 } _ { -0.38 } , A _ { 2 } = -1.36 ^ { +1.08 } _ { -1.41 } .
For all galaxy splits and IA models considered , we report cosmological parameter constraints consistent with the results of the main DES Y1 cosmic shear and multiprobe cosmology papers .