Distant Objects Observation by HST with Two Gravitational Lensing Galaxies Abell1689 and J1000+0221 Principal Investigator: Mr

Hubble Space Telescope Cycle 11 General Observer Proposal

General Observer proposal Distant objects observation by HST with two gravitational lensing galaxies abell1689 and J1000+0221 Principal Investigator: Mr. Lienong XU Institution: Wassamatta U. USA/NY Electronic mail: [email protected] Scientiﬁc category: COSMOLOGY Scientiﬁc keywords: GRAVITATIONAL LENSING, DISTANT GALAXIES, ABELL 1689, J1000+0221 Instruments: ACS, NICMOS, STIS Proprietary period: 0 Cycle 11 primary orbits: 40 Cycle 11 parallel orbits: 0

Special Proposal Types: Innovative

Abstract

This proposal is designed to acquire the HST to carefully observe those good gravitational lensing galaxies(Abell 1689, CLJ1226+3332) and the potential extremely distant astronomical objects which are exactly amplified by these galaxies. There is always great curiosity about how and what to observe the early universe. In recent years scientists found the gravitational lensing(GL) will be a promising approach. The GL is a direct consequence of Einsteins general relativity. The lensing will be significant on a cosmological scale and it can be treated as a powerful device rather than a pure cosmological effect. The intervening galaxies between observers and distant objects will act as a microscope for observers by its huge amount of mass. This technique offers a chance that those distant objects could be resolved and measured with basic quantities. Scientists have already made great effort to examine the proper lensing galaxies. The success of a team who previously used HST to take images of distant quasar with accretion disks also strongly encouraged the opportunity to better observe those far away luminous objects. The data collected of the distant objects will both provide deep insight of the earlier universe and reduce the uncertainties of current cosmological parameters. Mr. Lienong XU Distant objects observation by HST with two gravitational lensing galaxies abell1689 and J1000+0221

Investigator Institution Country PI: Mr. Lienong XU Wassamatta U. USA/NY CoI: Dr. Stan Theman U. Two Kurdistan CoI: Total number of investigators: 3

Observing Summary: Conﬁguration,mode,aperture Total Target RA DEC V spectral elements orbits Flags ABELL 1689 13h 11m 34.2s 01 21 56 16 IMAGING F270W 20 CPAR J1000+0221 150.077 +2.361 Visible/NIR IMAGING 20 CPAR (F606W, F814W, F125W, F160W Grand total orbit request 40

2 Mr. Lienong XU Distant objects observation by HST with two gravitational lensing galaxies abell1689 and J1000+0221

Scientiﬁc Justiﬁcation

It is always true that the further we see the earlier the universe we find and the better the level of our understanding of our universe as a whole both spatially and temporally. That is the ultimate reason why astronomers never stop to invent and improve those powerful telescopes in order to get clear images of distant objects. The better resolution we have, the more ambitious we are to observe farther objects. The primitive eagerness to look deeper contributes the great importance of this proposal. Due to Hubble flow, distant objects are highly red shifted (high z). By observing the galaxies with those high z values would help a lot for determine more accurate value of Hubble constant and acceleration rate of the universe. Gravitational lensing (strong) is a well-proposed method to satisfy the desire to look further in universe. The physics behind is simply that mass will bent the light governed by general relativity. Therefore the light from a distant object we see are deflected by the intermediate massive galaxies as lenses. The strong GL effect would cause multiple images of a single object or Einstein Rings due to light follows different paths. Careful mathematical calculation based on the lensing data can be conducted to derive the true information of the distant objects. This technique avoids the limitation of the telescope power itself. Instead scientists turned to find good candidates of lensing object in universe hence it is equivalently boosting the power of the original telescope. The scientists team CLASH(Cluster Lensing And Supernova survey with Hubble) and CLASS(Cosmic Lens All Sky Survey) has carefully searched and examined several massive galaxies and clusters which turned out to be qualified lenses. This achievement thus opened the window to probe those distant objects. Apart from more accurate measurement of those cosmological parameters, the clear images of the universe in early ages taken with the assist of gravitational lensing would probably provide certain objects whose physical structures including shape, size and chemical compositions are not well determined. Accretion disk(AD) from a typical distant quasar is a great illustration of realization of gravitational lensing. AD activates the radioactive polar jet from the rotational axis. It is believed that the polar jet events such as quasars are one of the brightest objects in the universe and the most energetic astronomical events. Thus a full study of this high energy but fundamental structure could tell us how physics works exactly at such large energy scale. Black hole also is involved in quasars and surrounded by AD. Definitely there is abundant information about black holes within the properties of AD . Despite the importance of accretion disks, the detailed structure of different types of accretion disks is poorly understood in terms of observation. What the astronomers achieved is several convincing models for the accretion disks base theories in physics. For those quasars, they are just much too far away to be resolved though their sizes are already incredibly large by model prediction. Once we are able to observe the resolved images of these objects, we can thoroughly test the fitness of current models and later modify the models of accretion disks and polar jets more realistic and precise. So far there is a team of scientists who successfully obtain several good quality images of far away accretion disc

3 Mr. Lienong XU Distant objects observation by HST with two gravitational lensing galaxies abell1689 and J1000+0221 exactly by the simple but powerful gravitational lensing technique. They really performed detailed measurement of accretion disks. These researchers roughly estimated the size of the particular quasar and details in deeper level like color change and temperature distribution across the quasars size. All the measurements showed a huge improvement compared with the traditional observation without GL. Above all GL observations do enlighten the prospective future development. The beneﬁt it produces deserves to use HST observation. Meanwhile it is also necessary to use the HST. The observing objects are really distant hence the measurement will be deviate dramatically if the observation itself contains too big uncertainties. Those negative factors caused by atmosphere should be avoided (using HST) in order to achieve idealized situation. On the other hand, the phenomena of gravitational lensing, even the strong gravitational lensing happens in a tiny region in the sky. Hence precise focusing is required and HST is so well-functioned to observe a small speciﬁc region for details. Description of the Observations

The proposed observation is designed to observe two galaxies, Abell 1689 and J1000+0221 which are confirmed to be good gravitational lens. The A1689-zD1 magnified by Abell 1689 is one of the most distant galaxies, the tremendously high red shift of this galaxies produce valuable data measurement for cosmological parameter and the early universe. The J1000+0221 is founded to be one of the most distant GL galaxies with a redshift about 1.53. High red shift lenses are rare. This increase the importance of detailed study of J1000+0221. The galaxies itself definitely contains enough useful information rather than the source object it lenses. These two galaxies are qualified representatives of GL and deserves to be observed with great details by the previous discussion in the scientific justification. Each of the galaxies is scheduled to utilize 20 orbits of the HST. The two targets can be directly pointed by RA and Dec coordinates. The calibration can be settled by checking whether it images show the GL effect such as multiple close indentical objects or Einstein ring. Images are supposed to be taken with V band, IR and NIR bands based on previous observation of these targets by HST. Near Infrared Camera and Multi-Object Spectrometer are necessary to catch the extremely faint source objects even though they are magnified by GL. The exposure times are chosen to be 100, 120 and 140 seconds. The relatively long exposure times are required because the objects are indeed very far away. It is better to collect more photons to make the images analyzable Though it would increase signal to noise ratio. After the Hubble observation, it is expected to gain enough high quality pictures of both the lensing galaxies and the distant source objects. By spectroscopy method, their respective redshift could be calculated. Uncertainties could be reduced compared with previous results due to more available and reliable images. Careful study of the Einstein ring could reveal the amplification of the source objects and further estimate the mass of the lensing galaxies. There is a branch of discussion here. The mass due to the lensing effect shall be bigger than the mass estimated by luminosity derivation, the discrepancies produced by the dark matters

4 Mr. Lienong XU Distant objects observation by HST with two gravitational lensing galaxies abell1689 and J1000+0221 which contribute huge mass. A reasonable fraction of dark matter to visible baryonic matter could be extracted from these data. All of these lensing galaxies measurements would be elaborated and future observation of potential new source objects beneﬁts from the precise information of the lensing galaxies. The distant sources objects, as mentioned before, are highly redshifted. A1689-zD1, the source object of Abell 1689, has a red shift 7.6 and distance 12.8 biliion light years. After the reobservation, the two numerical data precision could be enhance and produce better constraint on Hubble constant and acceleration parameter of universe expansion which is crucial for researchs about dark energy. The lensing images will show how the galaxies look like in the early universe and the spectral data could illustrate the chemical compositions of the galaxies. Scientists then would testify or improve current theory of the evolution of the galaxies. There is also target of opportunity of this GL observation, there may be other astronomical objects like quasars or supernovas lies exactly behind the lensing galaxies. In conclusion, so far the GL is the best way to observe the really distant objects we want. Also the development of this technique is already sophisticated. This oﬀers great convenience for data analysis. The expected measurements of the source targets will be fruitful ensured by their great distances. Special Requirements

I may require a lot of help, but I need no speciﬁc special scheduling requirements. Coordinated Observations

No, I’m pretty much uncoordinated. Justify Duplications

Abell 1689 was observed by HST in 2008 J1000+0221 was observed by HST in 2013 Previous HST Programs

None (and for good reason, too).