CAJ | 학술논문

通过利用CANDELS-EGS (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey-Extended Groth Strip)场中HST WFC3(Hubble Space Telescope Wide Field Camera 3) F160W高分辨率的观测图像，研究了9个光谱红极亮红外星系的形态结构特征.发现这些星系的形态表现出多样性(从椭圆到多个亮核或弥散的结构)，如：双核，气体桥，双不对称体，不规则或椭圆结构.为了定量地研究这些极亮红外星系的形态，测量了它们在静止光学波段的形态参数(基尼系数G和矩指数M20).与近邻极亮红外星系相比，高红移极亮红外星系的G偏小而M20偏大，表明这些星系的星族分布聚集度小且不对称性大.基于对样本中极亮红外星系2维面亮度轮廓的拟合，得到这些星系的有效半径分布在2.4 kpc到5.8 kpc之间，其平均值是(3.9±1.1) kpc.相比较于近邻相似质量的恒星形成星系来说，高红移极亮红外星系的平均大小要小1到2倍.在类似红移和红外光度条件下，得出的这些结果也与其它文献中给出的结论相一致.
통과이용CANDELS-EGS (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey-Extended Groth Strip)장중HST WFC3(Hubble Space Telescope Wide Field Camera 3) F160W고분변솔적관측도상，연구료9개광보홍겁량홍외성계적형태결구특정.발현저사성계적형태표현출다양성(종타원도다개량핵혹미산적결구)，여：쌍핵，기체교，쌍불대칭체，불규칙혹타원결구.위료정량지연구저사겁량홍외성계적형태，측량료타문재정지광학파단적형태삼수(기니계수G화구지수M20).여근린겁량홍외성계상비，고홍이겁량홍외성계적G편소이M20편대，표명저사성계적성족분포취집도소차불대칭성대.기우대양본중겁량홍외성계2유면량도륜곽적의합，득도저사성계적유효반경분포재2.4 kpc도5.8 kpc지간，기평균치시(3.9±1.1) kpc.상비교우근린상사질량적항성형성성계래설，고홍이겁량홍외성계적평균대소요소1도2배.재유사홍이화홍외광도조건하，득출적저사결과야여기타문헌중급출적결론상일치.
Using high-resolution HST WFC3 (Hubble Space Telescope Wide Field Camera 3) F160W imaging from the CANDELS-EGS (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey-Extended Groth Strip) field, we present the mor-phology analysis of 9 ultraluminous infrared galaxies (ULIRGs) at z ≈ 2. We find a wide range of morphological diversities for these ULIRGs, from spheroid to multiple bright nuclei or diffuse structures, e.g., double nuclei, bridges, dual asymmetries, irreg-ular, or elliptical structures. In quantitative, these sources show a lower Gini coe?cient (G) and a higher moment (M20) in the rest-frame optical morphology, compared to the lower redshift counterparts, indicating less concentrated and symmetric spatial distri-bution of the stellar mass of ULIRGs at z≈2. Moreover, we derive accurate effective radii of these ULIRGs through 2-D profile fitting, which range from 2.4 to 5.8 kpc, with a mean value of (3.9 ± 1.1) kpc. We find that the sizes of these ULIRGs at z ≈2 are on average one to two times smaller than those of the local star-forming galaxies with analogous stellar mass. Our results are consistent with those studies at similar redshift and infrared luminosity.