论文标题
首先了解SMACS 0723的JWST/MIRI 7.7微米源的性质
A First Look into the Nature of JWST/MIRI 7.7 micron Sources from SMACS 0723
论文作者
论文摘要
到目前为止，我们对MID-IR波长（> 5微米）处的阿加乳外宇宙的了解仅限于罕见的活性银河核（AGN）和最明亮的正常星系，直至Z〜3。 JWST及其中红外乐器（MIRI）的出现将彻底改变MID-IR政权作为探测高Z宇宙的关键波长领域的能力。在这项工作中，我们介绍了JWST Miri 7.7微米源的首次研究，从镜头群集smacs j0723.3-7327中选择了> 3 sigma显着性。我们用13个JWST和HST宽带对其光谱能分布拟合进行建模，以便获得所有这些来源的光度红移和派生的物理参数。我们发现，该7.7微米星系样品主要由高达Z = 4的正常星系组成，并且在较高的红移至Z〜9-10的尾部约为2％。我们的绝大多数星系具有[3.6] - [7.7] <0颜色，并且很少有人需要高灰尘灭绝值（a_v = 3 -6 mag）才能进行SED配件。结果透镜校正的恒星质量跨越10^7-10^{11} msun。总体而言，我们的结果清楚地表明，第一个Miri 7.7对深场的观察结果已经有用，可用于探测高红移宇宙，并表明，更深层次的7.7微米观测值很快将很快开放，这是第一次在中期波长处进行回报的时期。
Until now, our knowledge of the extragalactic Universe at mid-IR wavelengths (> 5 microns) was limited to rare active galactic nuclei (AGN) and the brightest normal galaxies up to z~3. The advent of the JWST with its Mid-Infrared Instrument (MIRI) will revolutionise the ability of the mid-IR regime as a key wavelength domain to probe the high-z Universe. In this work we present a first study of JWST MIRI 7.7 micron sources selected with > 3 sigma significance from the lensing cluster field SMACS J0723.3-7327. We model their spectral energy distribution fitting with 13 JWST and HST broad bands, in order to obtain photometric redshifts and derived physical parameters for all these sources. We find that this 7.7 micron galaxy sample is mainly composed of normal galaxies up to z=4 and has a tail of about 2% of sources at higher redshifts to z~ 9-10. The vast majority of our galaxies have [3.6]-[7.7]<0 colours and very few of them need high dust extinction values (A_V=3 -6 mag) for their SED fitting. The resulting lensing-corrected stellar masses span the range 10^7-10^{11} Msun. Overall, our results clearly show that the first MIRI 7.7 micron observations of deep fields are already useful to probe the high-redshift Universe and suggest that the deeper 7.7 micron observations to be available very soon will open up, for the first time, the epoch of reionisation at mid-IR wavelengths.
