ﻻ يوجد ملخص باللغة العربية
We have carried out near-infrared polarimetry toward the boundary of the Central Molecular Zone, in the field of (-1.4 deg $lesssim l lesssim$ -0.3 deg and 1.0 deg $lesssim l lesssim$ 2.9 deg, $|b|lesssim$ 0.1 deg), using the near-infrared polarimetric camera SIRPOL on the 1.4 m Infrared Survey Facility telescope. We have selected 112 intrinsically polarized sources on the basis of the estimate of interstellar polarization on Stokes $Q/I-U/I$ planes. The selected sources are brighter than $K_S=14.5$ mag and have polarimetric uncertainty $delta P<1,%$. Ten of these distinctive polarized sources are fit well with spectral energy distributions of young stellar objects when using the photometry in the archive of the Spitzer Space Telescope mid-infrared data. However, many sources have spectral energy distributions of normal stars suffering heavy interstellar extinction; these might be stars behind dark clouds. Due to the small number of distinctive polarized sources and candidates of young stellar object, we cannot judge if there is a decline of them outside the Central Molecular Zone. Many of massive candidates of young stellar object in the literature have only small intrinsic polarization. This might suggest that their masses are 4-15 M$_{{rm sun}}$, whose intrinsic polarization has been expected to be small.
We present a NIR polarimetric map of the 1deg by 1deg region toward the Galactic center. Comparing Stokes parameters between highly reddened stars and less reddened ones, we have obtained a polarization originating from magnetically aligned dust grai
We conducted near-infrared (JHKs) imaging polarimetry toward the infrared dark cloud (IRDC) M17 SWex, including almost all of the IRDC filaments as well as its outskirts, with the polarimeter SIRPOL on the IRSF 1.4 m telescope. We revealed the magnet
We present a spectroscopic follow-up of photometrically-selected young stellar object (YSO) candidates in the Central Molecular Zone of the Galactic center. Our goal is to quantify the contamination of this YSO sample by reddened giant stars with cir
Near-infrared polarimetry of point sources reveals the presence of a toroidal magnetic field in the central 20 x 20 region of our Galaxy. Comparing the Stokes parameters between high extinction stars and relatively low extinction ones, we have obtain
Previous radio observations revealed widespread gas-phase methanol (CH$_3$OH) in the Central Molecular Zone (CMZ) at the Galactic center (GC), but its origin remains unclear. Here, we report the discovery of CH$_3$OH ice toward a star in the CMZ, bas