HSC filters
Notes
- The MBQ1 (Medium Band Quadrant) filter is newly opened for open-use observations in Semester S26A.
If you wish to use this filter during the period of S26A through S27A, you must obtain an approval in advance from the filter developer team (see 'Contact addresses of user filters') and clearly state in your proposal that the approval has been obtained. - Narrow-band filters with their central wavelength shorter than 400 nm are not available in the queue mode because the autoguiding is apt to be failed. Currently, it applies to the NB387, NB391, and NB395 filters.
The following tables list filters available for open use observation of the HSC, together with their sensitivities. The transmission curves measured at the center of filters are available as plots and ASCII lists in the respective columns.
You may need to consider
- Quantum efficiency of FDCCD (plot) (table)
- Transmittance of the dewar window (plot) (table)
- Transmittance of the Primary Focus Unit of the HSC (POpt2) (plot) (table)
- Vignetting (plot) (table)
- Reflectivity of the Primary Mirror
as well as transmission curves below for estimating more exact throughput of each filter.
Sensitivities listed are for a 5 sigma detection measured in a 2'' diameter aperture in 1 hour of integration, assuming good (0.5'') seeing, dark (New Moon), and clear sky (transparency is 1.0). Please refer to the Exposure Time Calculator for sensitivities with other conditions.
Broad-band filters
| Filter | Center | Area-weighted mean |
Sensitivity (AB mag) |
mag for 1 e-/s |
SNR |
|---|---|---|---|---|---|
| g | Plot List | Plot List | 27.6 | 28.8 |  |
| r2(1) | Plot List | Plot List | 27.1 | 28.9 |  |
| i2(2) | Plot List | Plot List | 26.4 | 28.5 |  |
| z | Plot List | Plot List | 25.5 | 27.5 |  |
| Y(3) | Plot List | Plot List | 24.8 | 27.2 |  |
| (r)(1) | Plot List | Plot List | 27.1 | 28.8 |  |
| (i)(2) | Plot List | Plot List | 26.4 | 28.5 |  |
Notes:
- We replace the r-band filter to new one (HSC-r2) from Jul 28th 2016 (HST). We mainly used the previous r-band filter (HSC-r) till Jul 11th 2016 (HST). Please see "FILTER01" at the FITS header for checking which filter was used.
- We replace the i-band filter to new one (HSC-i2) from Feb 2016. We mainly used the previous i-band filter (HSC-i) till Jan 2016. Please see "FILTER01" at the FITS header for checking which filter was used.
- When you estimate a throughput of the Y band filter, you should consider the quantum efficiency of FDCCD, which is very low at >10000 Γ .
User filters
| Filter | Center | Area-weighted mean |
Sensitivity(1) (AB mag) |
mag for 1 e-/s |
Open(2) from |
When is it available without permission?(3) |
|---|---|---|---|---|---|---|
| NB387 | Plot List | Plot List | 25.1 | 24.4 | S16B | S18A |
| NB391 | Plot List | Plot List | 25.8 | 25.0 | S21B | S23A |
| NB395 | Plot List | Plot List | 25.5(4) | 25.2 | S21B | S23A |
| NB400 | Plot List | Plot List | 26.0 | 25.2 | S19A | S20B |
| NB430 | Plot List | Plot List | 25.5(4) | 25.0 | S20A | S21B |
| NB468 | Plot List | Plot List | 26.3 | 25.8 | S16A | S17B |
| NB497 | Plot List | Plot List | 25.7 | 25.5 | S20B | S22A |
| NB506 | Plot List | Plot List | 26.1 | 26.2 | S22B | S24A |
| NB515 | Plot List | Plot List | 25.7(4) | 25.7 | S15A | S16B |
| NB527 | Plot List | Plot List | 25.8(4) | 25.8 | S16A | S17B |
| NB656 | Plot List | Plot List | 25.4(4) | 26.0 | S16A | S16A |
| NB718 | Plot List | Plot List | 25.5 | 25.7 | S16B | S18A |
| NB816 | Plot List | Plot List | 25.2 | 25.5 | S15B | S17A |
| NB872 | Plot List | Plot List | 24.2 | 24.9 | S23A | S24B |
| NB921 | Plot List | Plot List | 24.8 | 25.5 | S15A | S16B |
| NB926 | Plot List | Plot List | 24.5 | 25.5 | S17A | S18B |
| NB973 | Plot List | Plot List | 24.3 | 24.9 | S17A | S18B |
| NB1010 | Plot List | Plot List | 22.9 | 24.0 | S18A | S19B |
| IB945 | Plot List | Plot List | 24.5 | 26.2 | S17A | S18B |
| EB-gri | Plot List | Plot List | 27.4(4) | 29.9 | S22B | S22B |
| MBQ1 | Plot Lists | Plot Lists | MBQ1-413: 26.4(5) MBQ1-439: 26.5(5) MBQ1-465: 26.4(5) MBQ1-490: 26.4(5) |
MBQ1-413: 26.4 MBQ1-439: 26.7 MBQ1-465: 26.7 MBQ1-490: 26.9 |
S26A | S27B(3) |
Notes:
- The sensitivity of a NB filter may be significantly affected by ununiformity of the transmittance curve across the field of view. Contact the filter developer team for details about the specification of a user filter.
- For user filters, during the first three semesters (or 3 call for proposals) after it is open to the public, people who are interested in using the filters must obtain an approval in advance from the filter developing team (cf. filter policy).
- If the semester is not passed, you need to obtain an approval in advance from the filter developer team (see 'Contact addresses of user filters') before you submit a proposal for open-use observations using the filter. You must clearly state in the proposal that the approval has been obtained.
- The values have been updated since the last update in June 2025.
- The values are still TBD.
Contact addresses of user filters (1) and Information for acknowledgement(2)
| Filter | PI | Fund | Fund number | |
|---|---|---|---|---|
| NB387 | Dr. Kazuhiro Shimasaku |  |
JSPS Kakenhi Scientific Research (A) | 23244022 |
| NB391 | Dr. Masami Ouchi |  |
JSPS Kakenhi Scientific Research (A) | 15H02064 |
| NB395 | Dr. Masashi Chiba |  |
JSPS Kakenhi Scientific Research (A) | 17H01101, 15H02064 |
| NB400 | Dr. Masami Ouchi | |
JSPS Kakenhi Scientific Research (A) | 15H02064 |
| NB430 | Dr. Masashi Chiba | |
JSPS Kakenhi Scientific Research (A) | 17H01101 |
| NB468 | Dr. Yuichi Matsuda |  |
JSPS Kakenhi Scientific Research (B) | 25287043 |
| NB497 | Dr. Yuichi Matsuda | |
JSPS Kakenhi Young Scientists (A) | 17H04831 |
| NB506 | Dr. Masayuki Umemura |  |
JSPS Kakenhi Scientific Research (A) | 19H00697 |
| NB515 | Dr. Masashi Chiba | |
MEXT Kakenhi Scientific Research on Priority Areas | 18072001 |
| NB527 | Dr. Ikuru Iwata |  |
JSPS Kakenhi Scientific Research (A) | 24244018 |
| NB718, NB816 | Dr. Yoshiaki Taniguchi |  |
Ehime University | |
| NB872 | Dr. Nobunari Kashikawa |  |
JSPS Kakenhi Scientific Research (A) | 21H04490 |
| NB921, NB973 | Dr. Masami Ouchi | |
JSPS Kakenhi Scientific Research (A) | 23244025 |
| NB926 | Dr. Masao Hayashi |  |
JSPS Kakenhi Young Scientists (A) | 26707006 |
| NB1010 | Dr. Kazuhiro Shimasaku | |
Toray Science Foundation | |
| IB945 | Dr. Akio Inoue |  |
JSPS Kakenhi Young Scientists (A) | 23684010 |
| EB-gri | Dr. Marc Buie |  |
NASA New Horizons | NASW-02008 |
| MBQ1 | Dr. Atsushi J. Nishizawa |  |
JSPS KAKENHI International Leading Research | 22K21349 |
Notes:
- Subaru Telescope accepts user filters. When you consider producing new HSC filters, please read the filter policy carefully, and contact Subaru Telescope (contact person: T. Terai
) well before applying for funds. - In a publication using these filters, please add the acknowledgement. For example, the acknowledgement for NB387 will be as follows.
The NB387 filter was supported by KAKENHI (23244022) Grant-in-Aid for Scientific Research (A) through the Japan Society for the Promotion of Science (JSPS).
Last Update: June 25, 2025