论文标题
互动系统NGC 7805/6（ARP 112）及其潮汐矮星系候选人
Interacting system NGC 7805/6 (Arp 112) and its tidal dwarf galaxy candidate
论文作者
论文摘要
我们介绍了巨大的巨型射电望远镜（GMRT）HI，喜马拉雅省Chandra望远镜（HCT）Halpha，1m Sampurnanand望远镜（ST）和130万个Devasthal快速光学望远镜（DFOT）深度光学观察NGC 7805/6（ARP 112）+TEST+TEST DEST DEST DEST DIST DESTID DIST DIST DISTID DIST DIST DIST DIST DIST DIST DIST DIST DIST DIST DIST+TEST DIST DIST DIST DIST DIST DEST DET -KUG kug kug kug kug kug kug kug Galaxy（TDG）候选人资格并探索相互作用系统的特性。我们的GMRT HI地图显示没有与Kug 2359+311相关的HI检测，也没有任何HI尾巴或桥梁状结构连接到NGC 7805/6系统。另一方面，我们的HCT HALPHA图像在KUG 2359+311中显示出强检测，并带有NET SFR〜0.035 $ \ PM 0.009 {\ rm M} _ {\ odot} \，{\ rm yr yr}^{ - 1} $。与〜0.015的NGC 7806的红移相比，HALPHA数据将Kug 2359+311的红移限制在$ 0.00 \ le z \ le 0.043 $。迄今为止检测到的TDG都很丰富，并显示了HI，离子化的气体和出色的潮汐碎屑步道（桥梁或尾巴），将它们连接到其父系统。但是，我们的HI数据和光学图像都不是比SDS更深的三个幅度，它揭示了将Kug 2359+311连接到NGC 7805/6的潮汐步道。与正常的矮星系相比，缺乏HI，存在旧的恒星种群，持续的恒星形成，SFR相当高，这表明Kug 2359+311可能不是ARP 112 TDG。在与ARP 112系统相互作用后，通常会经历形态转化的常规富含气体的星系经历形态转化的情况。从未来对Kug 2359+311的光谱观测的红移和金属性将有助于阐明这种神秘结构的性质。
We present results from our Giant Metrewave Radio Telescope (GMRT) HI, Himalayan Chandra Telescope (HCT) Halpha, 1m Sampurnanand Telescope (ST) and 1.3m Devasthal Fast Optical Telescope (DFOT) deep optical observations of NGC 7805/6 (Arp 112) system to test KUG 2359+311's tidal dwarf galaxy (TDG) candidacy and explore the properties of the interacting system. Our GMRT HI map shows no HI detection associated with KUG 2359+311, nor any HI tail or bridge-like structure connecting KUG 2359+311 to the NGC 7805/6 system. Our HCT Halpha image on the other hand, shows strong detections in KUG 2359+311, with net SFR ~ 0.035$\pm 0.009 {\rm M}_{\odot}\,{\rm yr}^{-1}$. The Halpha data constrains the redshift of KUG 2359+311 to $0.00 \le z \le 0.043$, compared to the redshift of NGC 7806 of ~ 0.015. TDGs detected to date have all been HI rich, and displayed HI, ionised gas and stellar tidal debris trails (bridges or tails) linking them to their parent systems. But neither our HI data nor our optical images, while three magnitudes deeper than SDSS, reveal tidal trail connecting KUG 2359+311 to NGC 7805/6. Lack of HI , presence of an old stellar population, ongoing star formation, reasonably high SFR compared to normal dwarf galaxies suggest that KUG 2359+311 may not be an Arp 112 TDG. It is most likely a case of a regular gas-rich dwarf galaxy undergoing a morphological transformation after having lost its entire gas content to an interaction with the Arp 112 system. Redshift and metallicity from future spectroscopic observations of KUG 2359+311 would help clarify the nature of this enigmatic structure.
