HSC filters

NOTES:

• The NB872 filter is newly opened for open-use observations from S23A.
• The sensitivity values have been updated based on the modified code of HSC ETC. (June 22, 2021)
• If you wish to use one of the user filters (i.e., NB, IB, and EB filters), you may need to obtain an approval in advance from the filter developer team. See 'Contact addresses of user filters'. You need to explicitly describe that you have obtained an approval in your proposal.
• 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 sensitivites. 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

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 (tranparency is 1.0). Please refer to the Exposure Time Calculator for sensitivities with other conditions.

Broad-band filters

Filter					Sensitivity (AB mag)	mag for 1 e-/s	SNR
Name	center		area-weighted mean
	Plot	List	Plot	List
g					27.6	28.8
r2(1)					27.1	28.9
i2(2)					26.4	28.5
z					25.5	27.5
Y(3)					24.8	27.2
(r)(1)					27.1	28.8
(i)(2)					26.4	28.5

Notes:
(1) 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.
(2) 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.
(3) When you estimate a throughput of the Y band filter, you should consider the quantum efficiency of FDCCD, which is very low at >10000 Å.

User filters

Filter					Sensitivity(1) (AB mag)	mag for 1 e-/s	Open(2) from	When is it available without permission?(3)
Name	center		area-weighted mean
	Plot	List	Plot	List
NB387					25.1	24.4	S16B	S18A
NB391					25.8	25.0	S21B	S23A
NB395					25.6	25.2	S21B	S23A
NB400					26.0	25.2	S19A	S20B
NB430					25.7	25.0	S20A	S21B
NB468					26.3	25.8	S16A	S17B
NB497					25.7	25.5	S20B	S22A
NB506					26.1 (4)	26.2	S22B	S24A
NB515					25.9	25.7	S15A	S16B
NB527					25.9	25.8	S16A	S17B
NB656					25.9	26.0	S16A	S16A
NB718					25.5 (4)	25.7	S16B	S18A
NB816					25.2	25.5	S15B	S17A
NB872					24.5 (5)	24.9	S23A	S24B
NB921					24.8	25.5	S15A	S16B
NB926					24.5	25.5	S17A	S18B
NB973					24.3	24.9	S17A	S18B
NB1010					22.9	24.0	S18A	S19B
IB945					24.5	26.2	S17A	S18B
EB-gri					27.3(4,5)	29.9	S22B	S22B

Notes:
(1) 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.
(2) 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).
(3) If the semester is not passed, you must obtain an approval in advance from the filter developer team before you submit your proposal using these user filters. See 'Contact addresses of user filters. You need to explicitly describe that you have obtained an approval in your proposal.
(4) The values have been revised since the last update.
(5) The values are still TBD.

Contact addresses of user filters ⁽¹⁾ and Information for acknowledgement⁽²⁾

Filter	PI	Email	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

Notes:

(1) Subaru Telescope accepts user filters. When you cosider to produce new HSC filters, please read the filter policy carefully, and contact Subaru Telescope (contact person: T. Terai [] ) well before applying for funds.

(2) 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: February 3, 2023 Copyright © 2000-2023 Subaru Telescope, NAOJ. All rights reserved.